I know a lot of the people I play with/know do NOT read the forums at all, but every now and then it's good to check the stickies in your class forums, because there are awesome posts about knowledgeable players that can help you out in your game.
Like this one on Affliction Spec Spell Rotation Guide: http://forums.worldofwarcraft.com/threa ... 6660&sid=1
Ultimate post for any affliction spec, whether you are 70 or 80 now, it definitely gives you a heads up on how to push out as much DPS as possible during battles.
For anyone who loves math, you should read this guys updated post from 3.0 PTR: http://forums.worldofwarcraft.com/threa ... 2735&sid=1
There he talks about the coefficients so you can maximize your gear through stats and damage based on your spell rotation (see the previously mentioned post), and you should be utterly destroying DPS' in your group.
At any rate, the main idea for affliction warlocks is that your dots don't do maximum damage until they have done their last tick. The worst thing you can do is kick off that last tick by refreshing the spell, because then it goes back down to the first one and repeats.
Anyway, hope that helps people. There are also gear posts, and the spirit change for warlocks is awesome.