It's really not too difficult. Just make sure you watch a few good YouTube videos first and take your time.
You need to make sure you get a reference style 660. These ones blow the hot air out the back of the card and not back into the case. EVGA do a lot of reference style cards so have a look at them. They look more enclosed than the other styles which have larger open fans
I'd get this and be done, it's the sc version for the same price as tigerdirects non sc with free shipping, and free game. Sign up for shoprunner at checkout and get 2 day free shipping. Go to cancel after a few days or they'll charge you, they'll be sad your canceling and offer you 3 more months free. They give you a chance to use shoprunner 3 separate times and then they give you a year free that's like 70$ value and 2 day free shipping all the time.