There are several ways to renovate your own home or buy a home and renovate it.
The first thing I would do is check with your city and county area developement division. They have federal, state, and city grants available. Usually these grants are no payments and no interest. Find out everything you can to make sure you are making the right choice in accepting one of these grants.
Second thing is trying to get a loan. There are some excellent loans available in which you can do a wide range of rehab, upgrades, and expansion.
These options have interest and require monthly payments. Even if you have not so perfect credit a FHA 203k loan may provide you with something to get what you need.
Then it is always a good idea to pay cash as well. But, if you can do that you may want to look into the grants first. They usually forgive the majority of the cost in 10 years. So it is almost like free money since you have no interest and no monthly payments. It all depends on the type of grant though so find out what is available.