If you want to go old school, use a 16 mm Bolex camera (if you can find one) then get the film developed (if any place will do it) then view it on a Moviola or 16 mm projector (again, if you can find them). Try looking in a museum. I think its fairly safe to say the days of film pencil tests are gone.
The easiest way is to use a computer with either a scanner, web cam or video camera connected by fire wire.
If you use a scanner, you need to be careful of the size of paper you use. Standard animation paper is 11 x 14. This wont fit onto most scanners. Your best bet is to work on 8 1/2 x 11 paper. Use the corner registration on the scanner and be sure that when you punch your paper, its always in the exact same position otherwise the drawings will jitter.
The other option is to capture the image using a web cam or video camera thats hooked up to the computer. Youll need some sort of camera stand to hold the camera steadily above the artwork. You also need a pegbar taped to the table top to register the drawings to. A couple of lights set up to properly illuminate the drawing would also be helpful.
Video Camera with Firewire
Here is a sketch of the basic set up that I have: