A Retribution Paladin Guide for PvE

Retribution is the Paladin spec that specializes in laying down the damage and it does that very well. Ret. Paladins can still throw out some weak heals and can, if careful, do some light tanking. Their primary role, which they do very well, is damage.

When Cataclysm launched the Retribution spec was alternately whacked with the nerf bat and boosted with the buffer. Eventually it settled down into a pretty solid damage machine.

I expect the same will happen when Mists of Pandaria launches, especially since that expansion will do a large scale remake of the talent system. Still, the new system should be much easier on the Devs, so maybe the swings from god-mode to doormat won't be quite so pronounced.

For a full Retribution Paladin guide you can hop over to GotWarcraft and get everything you need to know.

ElitistJerks also has a Ret. guide with all the usual number crunching and deep detail.

WoWpopular has a listing of popular Ret builds (and every other class,) including glyphs, gear, and more.

Retribution Guide for 4.3

The video says 4.2, but the author notes (in the YouTube text) that it is still just fine for 4.3. It covers stats, your build, and more.Also covered are various addons. The end of part 2 has a 5 minute DPS test, just to see what kind of numbers can be pulled on a target dummy.

Inscription Leveling

Here's a step by step guide to level Inscription, which also includes a lot of background on that skill.

To check out all of the Inscription recipes that are available, just go to WoWhead.

WoWwiki also has a guide that includes some of the various patch changes over time and other details.

Shockingly enough, Battle.net also has a page on the subject. 

Practicing Inscription