Pretty much what fuzy said lol. Ret if your botting because, well lets be serious its not like your going to die as a paladin lol and it will lvl you quicker via fasterkills, faster turn in's on quests. Prot by hand because you just cant beat instant que's on dungeons that yeild the same if not more experiance than 3 or 4 quests that you would turn in, and in less time.
I leveled 2 paly's from 1-90 together starting 14 days ago. I level'ed 1 as prot and 1 as ret. They both ding'ed 90 the same day. Yeah ret is a little faster, but it DOES die a few times. I used CLU.