Canon wide angle lens

hi Our daughter has just started a photography course at uni and has requested a wide angle lens for xmas. She has a canon SLR 300 and a canon SLR 350D What should we look for, what do all the different numbers mean, can anybody help and advise us.

That means your daughter have a film SLR and a Digital SLR. If you are tight in budget, you can consider Tokina/Phoenix 19~35mm f/3.5~4.5 lens, which cost about US$200 but works both with film and D SLR, also with a reasonable outcome. For budget under US$500, buy a Sigma lens. If you are willing to pay US$1000, a Canon EF 17-40mm F4L is a good choice. Have more $$$$$? Just go ahead for Canon's 2.8L gears.