You would probably be better off saving up a little bit of cash, and going with an FHA loan.
There are some programs out there for people with bad credit, but given everything that's going on - they're not as easy to get into as they used to be, and the terms are really not very good compared to even the 3% down option of an FHA loan.
Honestly, your best bet is going to be to do whatever you can to clean up your credit history over the next 12 months or so (you'd be supprised what even a year can do), use that time to save up a small amount of cash, and you'll be in a much better position.
I agree with the answers you have been given. FHA will be you best bet. The thing is no one knows truely how bad your credit is. It can be better than you think or worse as far as financing goes. The best advice I can give would to be to visit a bank or broker that has a reliable, and knowledgeable underwriter on FHA guidlines, then submit application, or get pre-approved.
Also if you qualify for FHA, check with your state. Many states in America have additional state funded programs to assist you with down payment to obtain a true 100% loan. I know mine does, and its the only program around town without a minimum credit score! Today, FHA guidelines have NO minimum credit score, however the banks buying and servicing their loans want to see a 580. Anything below must be manually underwritten by an actual person. And even then I doubt any manual underwrite will succeed under a 550 without unusual circumstances or state assistance. Good luck with everything!