Your 1st step is to get "pre-qualified" through your preferred lender. I would suggest seeing a Mortgage Broker if your credit is marginal. As, they will usually have many more options.
A trusted Buyers agent in your area can refer you to a Good lender that they know and trust.
If all else fails, a Lease/option can be a Great avenue to take if needed to accomplish your goal w/o waiting for your credit scores to be perfect and your varifiable income to be high enough for conventional financing.
L/O's in this market, can be a wonderful Win/Win opportunity for both Buyer and Seller. It's NOT a Sellers market anymore and L/O's can easily be mutually beneficial!
Here's another thought on creative financing: http://www.trulia.com/blog/leegoade/2011/03/what_is_creative