I'd recommend reading the EJ ret pally thread, at least. It's more oriented towards raiding, but a lot of what's in there will still apply. You'll still be using the same clash resolution and what not. A lot of the differences are getting to know your defensive abilities, though those things can certainly help in pve, as well.
http://elitistjerks.com/f76/t68951-retribution_updated_3_3_a/
I'll try to find some ret pvp specs. Though, you can pretty much get away with using any old raid spec. My spec is pretty much the cookie cutter raid spec with a couple points in Divine Purpose so I can HoF out of stuns.
I'd recommend hitting some heroics to get a nice 2h. Tyrannical Beheader from Pit of Saron is the you're going to get without raiding. There's a few other 2h that are decent that drop out of H TOC, and normal PoS and HoR. Hopefully your luck will be better than I had with my warrior. I was about to give up on it after several weeks of farming them all and not seeing one. Luckily the second Tyrannical Beheader only took another day or two drop after the first.
Protribution is also a lot of fun. That's pretty much gearing like a ret paladin aside from a 1h and shield. You don't have quite as much offensive capability as you would as ret, but you're pretty tough to kill. (Well, you might have more if you glyph for avenger's shield. I use my tank spec with tanking glyphs. I'm too cheap to go back and forth for pvp and then pve with either ret or prot specs

) I've heard
this guy is one to check out for that. He's currently in Tier 2 right now, but he's a good one to look at for gemming and what not. His primary spec is protibution. EDIT - Or follow the links in SPCTRE's post. Lots of good stuff there.
I've never tried Holy, but it seems ridiculous, even without a ton of gear. My brother re-specced his paladin to holy awhile ago. Even in junk blue gear, he was doing well. You'll be squishy until you get some resilience, but you can still keep people up. I've been tempted to try it out on my paladin. I love healing as disc on my priest in pvp. As much fun as it is to kill people, it's almost more fun to deny the other faction kills. Bringing people back up from a few % to full health so they can keep fighting is a blast.