First time home buyer information?

My fiancee and I are looking into buying our first home. I have no knowledge on where to start, what to look for, or how to go about it. I've been told there are loans you can get as a first time home buyer that doesn't require any money down. I make 25,000/year (+overtime) and my fiance makes 20,000/year. Anyone have any ideas on how big of a loan we could get. Any tips and advice is appreciated. Thank you.