I suppose my next question would be, which ram to get?
I could go the easy route and just order two 1GB sticks from apple.com, but that runs $370 with tax. I know on New Egg I could get them cheaper, but there are so many different kinda, I'm not sure what would be compatible with my iMac Core Duo.
You can go to http://www.crucial.com/ they have a section where you can choose the model of your computer and they will tell you which of their memory modules are compatible They guarantee 100% compatibility What I would do then is copy the model number and paste it in newegg.com and buy it from them.
edit: for that matter, Corsair has that on their site too: http://www.corsairmemory.com/corsair/configurator_search.html I like Corsair ram better than Crucial. Although both companies make a good product.
I ended up buying it from Crucial as they had a really good price on it, and I made sure it was compatible. Thanks for the help. Installation should be a breeze.