I usually go for the top sirloin you see in the butcher section at the supermarket, alot of times they can pre-marinade it for you right there.
Plug in the Foreman grill let it sit for about 3,4 minutes to warm up, mine usually makes a popping sound that way I know it is hot and ready.
Throw average thickness steak on for about 7,8 minues if you like medium rare, 9 to 10 will get you in the medium to medium well range.
I love my Foreman grill I use it at least three times a week but then again I eat ALOT of steak.
I'm actually surprised you are just now getting one, to be perfectly honest with you.