Depending on your computer, download either Mach2 (winXP or 2K)
http://www.artofcnc.ca or TurboCNC (DOS)
http://www.dakeng.com
These are the 2 most commonly used machine control programs. Mach2 has an excellent manual available for download as well.
For a small router, probably the best bet for drivers would be either the Xylotex (both bipolar and unipolar)
http://www.xylotex.com , or HobbyCNC's unipolar chopper. If you don't want to solder, the bipolar Xylotex is practically "plug and play". Be aware, though, that it is very intolerant of miswiring (as most drivers are).
Basically, you plug the Xylotex into the parallel port, connect a power supply and motors to it, start up Mach2 or TurboCNC, and start running. You can either run g-code files, or you can type in single line g-code commands.
Just noticed you said servo. Stick with steppers, much simpler to start with.