Check the STICKY'S for your chip and version xbox for bios.
Apps for xbox:
new dashboard - you decide, avalaunch, evolutionX, UnleashX, Nexgen, etc...
dvd2xbox - rips games to hard drive
dvdx2 - plays dvd's instead of using M$ dash
Xbox Media Center - name say's it all
You also want to learn how to use MIRC and get access to Xbins
Click here for instructions
That should get you started you need to do research and learn as much as you can about what your doing.
Later on you will want to get into emulators!
Floppy