If you onley want to lvl fast which you usually want when you've played another character. I would spec ret until lvl 40 where you can start to AoE grind.
If you want a prot build you should really pick up Holy shield and avenger shield to since you probably will tank in instances. Imp. Dev aura doesn't fill any markeble difference, there's a thread here which show you the mats. At lvl 70 it offers a tank with 12k armor only 1.59% higher mitigation, imo it's not worth 5 talentpoints.
If you spec protection you will probably AoE grind and tank in instances, so you should max your mitigation. http://www.worldofwarcraft.com/info/classes/paladin/talents.html?500000000000000000000502513052300152015015000505000000000000000 there's the finished build I would use if I speced protection. You may take benediciton if you want but imo it's not worth it, if you're tanking you'll get healed and you will not be low on mana. When you AoE grind you don't seal/judge that much. I put 5 points in Devine strenght for higher block rate, since your damage come from blocks at higher lvl.
Here's a vid off a lvl 63 Paladin AoE grinding, he explain good and shows you how it shuold be done imo: http://www.youtube.com/watch?v=2RIx7vDEGus
I'm not an expert, especially not on prot since I've only played holy.
Edit: excuse my spelling.
Edited, May 2nd 2007 5:13pm by Jordanprice