hey cameron welcome to the site
1) DON'T UPDATE YOUR XBOX if you want to play games from the hard drive. It has to be on a certain system menu
Check out
http://gmodz.ca/content.php?content_id=8&sub_menu_id=23Scroll down to "How do I know if my 360 can be JTAG'd to enable homerew?"
if you're xbox can be jtagged
go to
www.xbox360iso.com and ask there a lot of useful information on that site