Nature wildlife  A very nice site with a lot of pictures.
Alison Jones  Very beautiful pictures of African wildlife
Spooks photography page  Pictures of animals
On the Matrix  Pictures and facts on African animals
Ultimate ungulate page 
A large and very informative site on hoofed mammals. You can go direct to Even toed or Odd toed
Interesting information on bovids
Animal diversity 
About Bovidae
Wild cats  Interesting information about cats