noob pali...Follow

Well you have to decide how you want to level. Do you want to quickly kill 1 mob at a time or eventually try to get groups of lower level mobs. Holy really isn't a good way to level, unless you want to force yourself to learn how to grind/quest/etc. as a holy, like I did.

10-35 i would recommend Ret perhaps some points into Holy for Spiritual Focus.

35+ Protection becomes very smooth in terms of leveling thanks to having Reckoning maxed out. You can tank instances and level very smoothly, very nice build. Ret still is faster for leveling but not by much.

I wouldn't recommend Holy until lvl 60 or beyond. It is without a doubt the slowest leveling build, not just by a little but by A LOT. Really really really really painfully slow. Also their isn't the gear in Azeroth to justify it. After lvl 60 BC has gear to help it level but it is still the slowest.

End game you will either be Holy or Prot. Ret is getting a nice fix and will be much more viable after 2.3 but it will still have the stigma it has had for the last year and a half and in terms of end game content being a tank or healer is going to mean easier groupage than being dps.

my recomendation to you until lvl 25-35 go retribution because up until then the instancing a lot of the time wont be what it can be and slowly watching the enemy health bar depleat as yours barley move it is very boring so to remedy this folow these main tips first: grinding only= bad idea mixing questing,instancing,and some grinding is your best and most fun bet for leveling. Next when you hit lvl 25-35 start mixing potection with your retribution so that you wont go crazy when your alone but you will be prepaired if invited into a group
And this is the most important: remember talent points for a paladin are different than say a shammy or a druid in that we arent gimped in one feild if we choose another meaning a ret paladin can tank with flying colors. so remember you arent deciding you fate with talent point they just make you that much better at the feild you put them in