Shawn's answer is the best one so far. Other loan products take longer, but the reality is you need to know the shortest timeline, which FHA offers for both the shortest timeline for a Chapter 7 and a Chapter 13.
Just as important as the wait time is what you do to build credit after a bankrutcy to make sure you qualify. If you sit and wait 2 years and do nothing with your credit, your score will look the same as it does now, which is probably not high enough. It's very important that you open new tradlines NOW and treat them correctly.
Credit cards will help your credit the most if handled properly. With a recently discharged bankruptcy, you will likely only qualify for secured cards. A secured card is a credit card that's secured by a deposit. Deposit $100, get a $100 limit. If you don't pay, they use the deposit to pay it. They'll report the history just like a regular credit card to the bureaus. Most banks and credit unions will issue these.
Try to get 3 accounts RIGHT NOW. The longer you have them, the more they'll improve your score. Don't ever let the balance exceed 25% of the limit and always pay them on time. If you do this, your score will definitely be high enough to qualify when you reach 2 years. It's also important to see your credit now and make sure there are not inaccuracies, which are typical after a bankruptcy. You can get a free report at http://www.annualcreditreport.com and can dispute items on the bureau's site while you're looking at each of your reports.
I wrote the following blog post specifically to help consumers build their credit after a credit hardship, such as a bankruptcy or foreclosure. I hope this is helpful. Good luck!
If its a chapter 7: FHA and VA, 2 yrs. Conventional/Fannie Mae, 3 yrs
If its a Chapter 13: FHA and VA, 12 months with court approval. Conventional/Fannie Mae, the same.
If a property was included in the Chapter 7, 3 yrs. For Conventional/Fannie Mae, its 5 yrs.