Canon Rebel K2 compatable lenses?

Will the "Tamron Autofocus 75-300mm f/4-5.6 LD with Hood for Canon SLR Cameras lens" work on a Canon Rebel K2?

SLR lenses?

I'm quite new at photography and I will buy a 35mm SLR.(probably Canon Rebel K2). I really don't know about lenses and need to learn about them. For example what is the difference between a 28-80mm lens and a 50mm lens? and what do those numbers represent?

Thanks in advance for your help.

Are these lenses any good? (for 35mm camera)

I'm looking for a wide-angle lens and a fish-eye lens of some sort for a Canon Rebel G. I'm not sure if they make real lenses for this thing or if this is just how they are for older cameras.

Are any of these decent?

http://cgi.ebay.com/pro-fisheye-lens-fits-canon-rebel-g-gii-2000-eos-slr_W0QQitemZ110276967851QQcmdZViewItemQQssPageNameZRSS:B:SRCH:US:101#ebayphotohosting
http://www.amazon.com/Opteka-Angle-Panoramic-Macro-Fisheye/dp/B000HVD8D8/ref=sr_1_4?ie=UTF8&s=photo&qid=1218500446&sr=1-4
http://cgi.ebay.com/WIDE-ANGLE-LENS-For-CANON-EOS-Rebel-2000-ti-G-GII-K-K2_W0QQitemZ130245392195QQihZ003QQcategoryZ3323QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

Are there any better options out there for this camera?