locally foreclosures HUD and most others list with an Mulitple listing broker when they are ready to be sold, so they will show up on what we call local IDX websites, bottom line most local brokers will have them on their website, my site c21jerry.com participates as an IDX and has those listings also you can go on Hudhomestore.com for HUD listings specifically, to buy one you need a approved HUD vendore of which my firm is one,
Any other questions do not hesistate to ask, Jon Appleby listed below is an excellent mortgage broker who I recommend often, and would be an excellent source for a pre-approval, feel free to call me if you have additional questions.
Being organized and having all your documents readily available prior to looking will save you a tremendous amount of headaches and aggravation as you begin your search.
As far as down payments those depend on the type of loan you get. You should go speak with a couple lenders to get familiar with the types available and what you qualify for, you need to include a lender letter with most bank owned offers to show you have spoken with a lender.