Clerics are just like Priests in Ragnarok Online or World or Warcraft or any healing class you've ever played. They're made to buff and heal their allies while they take whatever is you're fighting down.

The Simple Rundown:

Stats:
(The Full Support build)
STR - Low to Moderate (Secondary stat)
DEX - DO NOT TOUCH
INT - HIGH (Main stat)
CON - DO NOT TOUCH
CHA - DO NOT TOUCH
SEN - DO NOT TOUCH

(The Full Support-Battle Hybrid)
STR - Moderate to High (Secondary stat)
DEX - DO NOT TOUCH
INT - High (Main stat)
CON - Low to Moderate
CHA - DO NOT TOUCH
SEN - Low

(The Dex Hybrid [BOW])**
STR - Low to Moderate
DEX - High
INT - Moderate to High
CON - Moderate
CHA - DO NOT TOUCH
SEN - Moderate

(The Dex Hybrid [KATAR])***
STR - Moderate to High
DEX - High
INT - Low to Moderate
CON - Low to Moderate
CHA - DO NOT TOUCH
SEN - Moderate to High

There are several other builds for a cleric, but some have not been successfully tested out. I do not have numbers here because numbers depend highly on a person's interpretation of what a "low" amount of STR is and etc.

** The build is meant mostly for battling and some supporting, INT can be varied as per what the person wants to do.

*** This build is meant for battling like Bow and it can be used interchangeably between swords and katars although for katars I recommend a higher amount of STR, since they are meant for speed, not power.

Note that there is a STR build, but that build doesn't seem to be too common among the masses, I will cover it here though.

Skills:

As a cleric you want to make sure you serve some of your purpose even if it's just on yourself.

By level 70 this should be your skill tree:
Meditation 10
Support (Rapid Run) 5
Power Support (Attack Up) 5
Hit Support (Accuracy Up) 3
Cure 5
Heal (Party Heal) 5
Blessing Body (HP Up)* 5
Blessing Mind (MP Up)*2
Enchanted Armor (Defense Up)** 4
Bonfire 5 (This skill is optional to dex clerics, but not recommended.)

Skills that are NOT recommended:
Curse***
Summon Mastery****
Phantom Sword****


* These are known as the party-buffs, they can only be used on party members (or yourself if you're alone.) They are pre-requisites for skills later on, so make sure to get them

** This skill is a SELF-BUFF, which means you can't cast it on anyone but yourself.

*** Curse is the most useless skill a Cleric will ever get, if you wanna get it for fun later on though, be my guest.

**** Summon Mastery and subsequent skills are pretty useless early on, but I have heard reports that they can be good if you use the correct build.

Recommended leveling areas:

1-12
Adventure Plains and Birth Island of course, I recommend staying here until 8, but if you're paranoid, then be my guest and level until 12-ish here, it makes changing jobs that much easier.

8-16
This level range is best spent in the Valley of Luxem Tower, it does give you some decent drops and EXP.

12-19
Zant is your destination, it becomes pretty easy once you're hit 18-ish, but it's up to you if you wanna leave the area early

17-25
This range offers two options, El Verloon Desert, or Breezy Hills. If you choose the Desert, then don't bother with Rackies they make you use pots unnecesarily, and are annoying. Head for Turtles, I recommend at LEAST being 20, but if you wanna go earlier, why not? Should you choose the hills, then level on Pomics from 17-20 and move up to Rackies inside the door at 20+

25-33
Lake of Anima is HIGHLY recommended at this stage, particularly porkies from 25-30, and MAYBE Aquas, and if you're brave enough, the Aqua King.

33-45
This range offers two options, you can beat up Moldies for a while OR, go to Grunters, which are a bit tougher. Moldies are cake at 33 or so, so I recommend staying there, but if you choose to go to Grunters then I recommend moving in all the way to the left since that's where the Grunter King appears, and he gives GOOD experience, and every so often a nice little drop.

40-55
This range is the fork in the road since, depending on your build, it can be difficult or easy for you. There are quite a few options you can take once you hit this range:

1. Grunters - The can get you all the way to 45 or so.

2. The Forest of Wisdom - You're good there until around the late 40's

3. Mt. Eruca - This is up on Luna, YOU MUST be 45 to go to Luna. Great Experience between 45-70, but no drops PERIOD.

4. The Goblin Cave - Decent Experience, good drops for a lot of things later on, this area's recommended if you're collecting items for crafting.

5. Kenji Beach - Recommended for people 50+, decent Experience, good drops, and a few Kings appear here namely: the Krawfy King, the Junon's Dungaliath (aka the Junon's King Kong).

55-70
This range is more difficult for Katar Dex clerics since the monsters from this point on begin to get heavy on the HP and defense. Once again, this range offers you several options.

1. The Goblin Cave (B1 Last Room or B2) - This options is kinda difficult, but if you want to challenge yourself in B2, be my guest, it pays off in the long run with a lot of drops, but I recommend you get a good party since the monsters get a bit difficult, especially if you're a full-support cleric.

2. Mt. Eruca - This is the easiest option, but it's going ot make it kind of hard for you to get any money, so if you have a decent amount collected for 2nd job change, go ahead, but if you're broke, then I recommend elsewhere.

3. The Gorge of Silence - The most recommended area for people in this range, good drops for those of you who are broke, but a warning to Dex Clerics: this area's monsters are really heavy on the defence, it's recommended for Bow Clerics and Full Supports. Party is recommended here.

70-84

This level range offers you two options, you can stay on Junon for a little while and continue until 80-ish, OR you can head up to Luna and fight slags between 70 and 78-ish.

84-99

This range has you pick fighting, Shadow Wolves and Yetis, along with Yeti Riders when you hit the late 80's, a note to you is to watch out for the Ruper Mages, the have a nasty little AoE, BUT they ARE easy to take out.

99-110~

Notice I put the tilde (~) there, that is because you can choose to change areas midway in this range, between this range I recommend you head out to the Winter Mauls and Elder Frost Worms, HOWEVER you CAN head out to Freezing Plateau and fight Elder Mammoths as a group at around 105 (ONLY RECOMMENDED FOR FS CLERICS).

110-130~

At this point you can head out to Freezing Plateau and fight Elder Mammoths and Dreadnaught Kings for a while. The Behemoth King ALSO appears in this area, but trust me, IT IS NOT recommended you try that monster. Also note that you could go to Eldeon, you can opt to try fighting on Eldeon at 125-ish, but for the most part you can stay here until 135 or so.

130-150~

This range offers two options, you can stay in Xita and fight Pincer Queens and King Hooks, OR you can try your luck at Shady Jungle, but I recommend Xita.

145-155

At this point you can opt out of Xita and head out to Shady Jungle, OR you can stay in Xita and fight in the upper-left corners of the map, or head up the little village in the middle of the map and fight Sikuku Spearmen, Shaman, and etc. whatever you choose is up to you.

155-165

This range is critical, and LONG, it always is before you get to a checkpoint in the game. This is the range before you get to the Sikuku Underground Prison. This range has options:

1. Forest of Wandering - You can try your luck with Sikuku Tiger Assassins and the like. I recommend being at least 160 before even attempting this area, as it CAN get kind of rough, especially for FS Clerics.

2. Sikuku Gargoyles - If you can make your way to the outside of the prison, then congratulations you deserve to be here. Drops are pretty decent too.

3. Oro - The 4th Planet, with a Mage or a Knight you get some pretty decent experience with their AoEs, drops are decent at best though.

165-195

Congratulations, you can get into the prison, however slow your roll there hotshot. I don't recommend going in right of the bat, as most players want someone who is at LEAST 175+, BUT if you can get a party that's good because it offers some of the best experience in the game.

You can also choose:

1. Oro - Try your luck on Oro AGAIN :D

2. Sikuku Gargoyles - At this point you should be able to make it here even if it's not totally intact.

3. Sikuku Destroyers/Killers - This monster is recommended for those 170+ who think you're not quite ready.

195-210

It's recommended you head up to Oro now, they should be pretty easy monsters, But the prison at this point offers a few options, although they can be pretty dangerous to get to.

1. R1 - This room is still an option, but at 195 experience REALLY drops.

2. R2 - Better EXP than R1 and since there are fewer people who dare try, the drops are pretty awesome.

3. R3 - This is the hardest room to get to, and if you can't survive getting here, then I recommend staying in R1, or R2. Full Support clerics will find it insanely difficult to get here unless they have ghost potions.

210

CONGRATS you're 210

Recommended Gems:

FS Cleric: Topaz[7] (AND) Diamond[7] in your staff**
Dex Cleric: Garnet[7] (OR) Emerald[7] (OR) E[7] + 3 G[7]

** For Hybrids Only

Skills:

By the time 165 your skills should look something like this:

Meditation 20
Cure 10
Heal 10
Support 10
Power Support 10
Hit Support 10
Bonfire 7
Blessing Body 10
Blessing Mind 10
Enchanted Armor 10
Ressurection 5
Battle Support 10
Damage Support 10
Sharpen Support 10
Defense Aura 10
Magical Aura 10
Evasion Aura 10
Purify 3
Curse 10

(This is based on a build that DOESN'T get any side-skills like Mana Bolt and Magic Arms Mastery, if you do, then you're on your own and your final result at 165 may vary from the one above, don't come crying to me if it does either, I provided you the basis and if you chose not to follow it, that's your problem :P.)

After you have your skills like shown above, then you can free-reign and gather whatever skills you want, or even save up the points, whatever you want. By the time you hit 165 your main stat should also be maxed (300) or close to it, and you should be working on your secondary stat or other stats.

Also note, that for the battle (dex) builds the final skill result may vary as they are recommended to get skills from the Spell Mastery tree to fight (mainly Fire Ring and maybe Mild.)

And that's the end of my guide, PM me if you want actual numbers.

Not bad.

~Dark

EDIT: If anyone is reading this, I'll just say this: ALL GUIDES WILL BE PINNED. Thank you, and pinned.

EDIT: What the heck was I thinking. Un-pinned, if anyone has any complains, tell me.