you have to install a dashboard and some apps to copy backup games to your hdd.
there are many dashboards out there just try them and see which one you like and use it.
to install a dash just ftp them over to your hdd and setup x3cl to the boot order and drive letter that you copied them to.
for a first timer, i would suggest Slayer's 2.6 it will install a dash and some usefull apps for the backup game stuff.
also you will need to have a larger hdd in your xbox, because you aren't going to get but a few games on it with the stock one.
go to xbox-scene and read the tuts on how to do the things that i have suggested.
hope this was some help.
and remember to read and reread the forums. all the answers are here and on xbox-scene tuts. if you don't then be ready to get flamed.