Hmm, the addon that I will recommend doesn't put up a lot of text on the screen, but it does show you with images what your next few casts should be. For Affliction you'd get something like this:
The add on that does this is called Ripped and it has a specific module for affliction warlocks. You find both on Curse.com:
http://wow.curse.com/downloads/wow-a...ls/ripped.aspx
and
http://wow.curse.com/downloads/wow-a...ails/arws.aspx
I think that you'll find that over time, once you get a feel for what the proper affliction rotations are, you won't need this addon anymore. It's kind of like training wheels on a bicycle. Have fun.