On graphics

I said to use either low or medium, but I neglected to mention the even better option of hybrid.

You can't get hybrid graphics via the in-game menu though, you have to actually modify the graphics file manually. Instructions on how to do so are here

http://www.teamliquid.net/forum/starcraft-2/442848-hybrid-settings-20

I recommend using these, but you don't have to by any means. It should take between 2-10 minutes to get these working (it would take me only a minute or two because I've setup hybrid graphics a lot, but for your first time setting them up it might take a bit to figure it out)