I feed chicken, mostly. The two websites I gave you will give you information on what types of foods are best, as well as what type of supplement you might want to consider. There is a supplement that I use called WildTrax, which was fairly inexpensive, so it may be worth it to get it and use it even if it's not necessary, and just add a little bump in the raw. If you're not going to feed raw every day, you may not have to go through the whole process outlined on the websites I sent. Mostly, I'd get a few boneless, skinless raw chicken breasts and thighs. Try cutting them down into very small chunks. You might want to consider flattening them, and then freezing them about half solid. It makes cutting a ton easier.
The supplement I mentioned above can be bought online at jefferspets.com I believe. It was about $18 for a four pound container, and I bought one of these in December and I'm only now getting down to about half way through it.
If you're going to feed raw more often, you'll definitely need a supplement, and you will probably want to start adding liver and organ meats, totalling about 10% of the overall weight. I'd suggest chicken liver/organs.
The two websites give you tons of information about diet, as well as the benefits of feeding raw diets, and a whole list of links that you might be interested in (including some premade raw sites). You may just want to get premade raw, specifically made for cats, as they're already balanced, and/or ground, and they're, in theory, ground on clean equipment.
I don't have any direct websites to premade raw, as I make all of my own raw and don't buy it premade, but they seem to work well except for cost for those that do. If you're only feeding it sometimes, though, you probably won't run into as much of an issue with cost.