My credit is great, husbands is bad but he's the one with a job can we get a loan?

[carmac]

My credit is in the 700's, I just pulled husbands transunion score and its 600. We are first time home buyers. Will they only look at his credit because he has the income? I have been a homemaker for 9 years. He had three medical bills (collection agency) from 2004 that had not been paid on (total under $500) , I just paid these off. The only other thing on there (in the good section) was a car loan we had from 1997-2001. Will it take over a year to get his credit up 50 points? ( I know we will qualify if his score is 640). We are thinking of getting him a secured credit card for $500. Is there anything else we can do?
Just wanted to add that I don't have any credit cards.