Just buy Norton or some other anti-virus, and install it. Other than that, the computer comes with a warranty, so you should be ok without Geek Squad.
I just paid for a one year Geek Squad maintenance contract, because my laptop had viruses. It included purchase and install of an anti-virus of your choice (I chose Norton) and it includes not just taking the laptop in for maintenance, but phone assistance 24/7 for one year. However, my laptop is not new (and for the $199 price for the one year contract, it was a close toss-up between the $199 contract or buying a new laptop. I figured I’d do the one year maintenance and then buy a new laptop (or get one for Christmas) in 2012.