Most lenders are going to want a middle scrore of 620. If you are married, they will take the lower of your two middle scores I believe. Most lenders are also going to want nothing late in the last 12 months atleast.
In addition to paying past bills, you need to have some positive lines of credit. That will raise your scores but usually only after having them for 12 months or more.
One baddie inside of 12 months shouldn't be that much of a problem, although uw may want a letter of explanation. If you're recovering from bk...that could be a big issue.
You're not giving us a lot of information to go on. Do you have other cc with zero balances? Do you have any collections? Recent baddies?
I also recommend going to the rebuilding board and posting more details regarding why your score is as low as it is. There are a lot of things that could be done, depending on what is actually bringing your score down, and some are easier than others. Everyone here will be very good at recommending the best course of action for increasing your scores.
As someone already mentioned, 620 should be your target as that will get you at least one step closer to qualifying for an FHA loan. While the FHA loan itself does not have a minimum requirement, the lenders that actually fund the FHA loans typically use 620 as a minimum. In the past you could get one with a 580, but that has changed in the last couple months and it is now very hard to find a lender who still uses 580 as a minimum (the few that do remain will likely increase to 620 in the near future).
I wish you the best of luck. It can be done, but it may not be easy!