Nutshell answer:
Vendors -- rodentpro; hare today; mice direct (ask for non irradiated prey); quailandmice.com. There may be commercial interests near you. Quailandmice.com is 30 minutes from me. I get my quail from them and rats, etc. from rodentpro. Shipping can be very expensive depending on your location.
Tips -- start with small critters -- fuzzie mice, chicks, and work your way up to larger prey depending on your cat's ability and until its jaw muscles get strong. My F6 is 11lbs and eats adult quail without a problem. If your cat will eat only the smaller, immature prey, you should supplement with vitamins. Once the cat gets used to eating whole prey, the cat's appetite may increase a whole lot for the first month or so and then levels off. Your cat will probably need to be taught that the prey is food. One trick often used is to tie a mouse or chick to a string and play with the cat like you would with a feather wand. It normally doesn't take long for the cat to get the picture. Sometimes a cat will get diarrhea as its body gets rid of stored toxins and cleans itself of stored fillers present in commercial food. Doesn't last too long and before you know it, the cat is pooping less and its nearly odor free.
Stories -- I transitioned 2 DSH kibble addicts (12 & 14 yrs old) from kibble to canned to raw to whole prey. In the 2 months it took, their coats and energy level improved, dandruff disappeared and they acted like kittens again. The 12 yr old also had Inflammatory Bowel Disease and the beginning of chronic kidney disease and the vet told me a raw diet would kill her. She was 18 when she died 4 mos ago due to kidney failure. I'm convinced she would have died much sooner had I kept her on a commercial diet. It really is amazing to watch the change.
Also, check out
http://www.rawfedcats.org/practicalguide.htm for a bit more detail.