The EOS 5D Mark II is compatible with all Canon lenses in the EF lineup (except EF-S lenses).
What type of photography you are wanting to do will eventually dictate the direction of what lenses you will need. A fast lens of f2.8 or faster with a high zoom of 300-600mm for sports and wildlife photography. 28Mm to 100mm for portrait type work. 10-20mm (one of my favorites) is great for artistic photography and wedding photos.
That being said...some good starting out lenses are :
Canon - EF 28-105mm f/3.5-4.5 II USM Zoom Lens. Good to just leave on your camera as a carry around lens. Nice for portrait work and general landscape. More about the lens here:
http://www.bestbuy.com/site/olspage...Canon - 75-300mm f/4-5.6 III Zoom Lens. OK for basic sports photography (if you raise the ISO on the camera up high) and some wildlife photography. Not a very fast lens, but the price is good. More info here:
http://www.bestbuy.com/site/olspage...When it comes to lenses...FASTER IS ALLWAY BETTER. However...that speed comes with a prices tag. But believe me, it's worth it. Having a f1.4 lens in a low light situation and getting that image just right verses a grainy image from the ISO being too high makes a BIG difference.