Seconded, it's a relatively simple procedure.  Just a couple safety tips
to remember:

When you're working the nuts on the terminal clamps, be careful not to
let your wrench touch the other terminal(!!!!!!!!). Also, it's best to
remove the negative terminal first, as it's connected to the body of the
car, and if you remove the positive with it still attached, there's a
greater chance of your wrench shorting to the body.

Once the terminals are off, a cleaning brush like the one pictured here:
http://media.wiley.com/assets/3/47/fg0-7645-5089-6_0306.jpg will do a
good job of cleaning them and the posts.  Should cost about $3-$4 at any
auto-parts store.

While you're at the Autozone (or your store of choice), pick up some
terminal grease as well - it's a dielectric grease that you use to cover
the posts to keep the air away and prevent corrosion.