maxing dps

maxdps.com

easy to use: pick your class and spec, put in your stats and see what you'll be putting out.
that's not the main way i use it though...
on the left, check all the boxes of dungeons you can do and clear; along the bottom of the page you can see the BEST dps gear from any raid/dungeon you checked for your build and how you should gem them to max out yo shit. It's nice to have open in a raid for quick reference if you're not sure if it'll be an upgrade or not.

This should help cut down on people picking up mainspec pieces that could be sharded because they actually already have better gear. more shards!

mages locks and retadins (lawlwat) should go check out a program called rawr
its like a simplified spread sheet that more acruatley ranks upgrades to match with the gear you alrdy have

maxdps is decent for a straight piece to piece comparison (at least for shamans, I can't speak for other classes), but it doesn't take your entire set into account and takes liberties with things such as being hit capped etc. whereas Rawr loads your entire set and can also be used for a piece to piece evaluation. Rawr also has some tank modules, which I know tanks appreciate. That being said Rawr.xxxx is programmed by the separate communities and not all specs/classes have one as of yet, but if your class does, it's a great tool.

http://codeplex.com/Rawr