First Time Priest

I played during WOTLK extensively during retail, and have played extensively on Warmane...pretty much every class except druid and priest. I played a pure disc priest during Cata, but NEVER went out of the spec and only played it maybe 100 hours, total.
Well, I rolled my first priest the other day - I'm almost 20, now - and WOW. What an awful experience so far!
I don't heal well, yet. I can't disc well, yet. And I can't really DPS well, yet.

I'm speccing to Shadow (I was a Afflock main for 6 years on retail and 2ish years between Warmane and other private servers) and so far I'm just getting frustrated with it. I literally only can pull one mob at a time and realistically only have 3 DPS spells which don't do much.

Not giving up, just venting :)
I hope to God it gets better! ....does it?

The Priest leveling experience is easily the worst class leveling experience you can have in the game. What I can tell you, though, is that once you do get the character leveled, it is also easily the most rewarding class to level. Everyone loves to have a Priest of some kind around, not just for the class buffs, but for what the Priest specs are capable of doing for their groups. It's not just that though. Having a max-level Priest and doing group content with one just *feels good*. I'm not too sure how I can explain or quantify the experience for you, but if you commit to it, you are in for a wonderful time.

I just hit 80 on priest, took till I could get shadow form for things to even out for me. By the time I hit Outland I was pretty solid and could take on a few mobs if it came down to it. Biggest problem for me was constantly OOM, needed a lot of drinks and every single possible talent to save you mana to speed up your leveling. You will notice the same in dungeons, you need a ridiculous amount of spirit or a mage/pally to buff you otherwise you will OOM every other encounter.

Get spirit tap/improved tap, shadow focus, focused mind in shadow talent spec and also get up to meditation in the disc talent tree. Always make sure you get the last hit to ensure you get spirit tap to proc, use your wand to save mana when mobs are low, avoid excessive use of Power Word: Shield as it costs a lot of mana and defeats the purpose of you regaining health from your shadow damage. Basically, don't be afraid to start a fight at 30-40% hp, as you can regain at a good rate once your damage starts rolling. Also need improved shadow form to reduce knock back without shield which speeds up killing.

Hope that helps and good luck :D

Leveling as dps Holy can make a huge difference until you're high enough to get all the good Shadow spells.

Pretty much what is posted in the link, which I found via Google.
http://holyfirespec.blogspot.com/200...-guide-32.html

Priest is a blast on 80. Keep it up mate! Both holy and disc are great in raid. Disc being kinda boring since you only spam one button whole raid except for some cooldowns. Holy is great. And shadow dps is insane aswell and you will be wanted in raids for vampiric embrace and soaking etc

I can relate. Playing wotlk since its release and few weeks ago made my first priest. First 20 levels were awful. Constant oom, can't kill more than 1-2 mobs at the time.

Now i am lvl 48, now i can pull as many mobs my mana allows. In dungeons i constantly have to sit down and drink.

Also don't be afraid to go as healer in rdf while putting talents only in shadow. If tank can hold the aggro and does not pull entire instance you can manage with shield + renew. (If tank outlevels instance you can heal with dots :D )