Achievement Hunter has a great set of videos - often more helpful with some Holocrons, and the witty remarks add flavor - at http://ah.roosterteeth.com/games/swforceunleashed/
that don't really need repeating.
What I do want to warn you about is the "default text glitch" discussed in some detail - though take any assumptions about how this happens with a grain of salt since nothing has been proven and every assumption has been proven wrong - at http://www.xbox360achievements.org/forum/showthread.php?t=91...
What even the Lucas Arts support page states is that you should make a backup periodically. What I did is after every mission right after you regain control, click the Back button, select the mission stats, and make sure the first objective doesn't read "* default text". If not, exit out of the game, go to the System blade, select Memory, then your Hard Drive, then Games, then find "The Force Unleashed". Select it and copy it to a MU. If the "* default text" shows up, reload this save. Always load the game off your hard drive when actually playing the Force Unleashed, however. Don't corrupt your backup. It's only 320K - at least for both 1 and 2 game saves (haven't created any more myself) - so it doesn't take much.
This usually happens on the last level, but some have reported it on earlier levels and it appears it's not just limited to the Xbox 360.