I think that really depends on the kind of cut you want. If you are willing to get it really short, then a set of electric clippers is going to get you high and tight in a matter of moments. If you want something evened and thinned out all over and still a couple inches long in places, you'll need scissors too.
If you was convinced to do it yourself, use the clippers and get it to stubble. You are unlikely to get it looking right in the back with scissors.
I cut my own and others hair many times trying to get past inspection while in college.
Something like this might be good:
http://consumer.wahl.com/product.cfm?sid=9&ID=87