You go to your county courthouse for tax foreclosures.
Question: Why are you looking at foreclosures? And, within foreclosures, why tax foreclosures? Of the foreclosures I'm aware of, only a very tiny percentage are tax foreclosures. And often the tax foreclosures are small slices of land, or landlocked parcels, that aren't worth much. Like I said, you can get that from the county courthouse. One other thing to keep in mind about tax foreclosures: Many jurisdictions only offer them (often via an auction process) only once a year.
And why foreclosures? I know some people have this image of foreclosures being great bargains--sometimes they are, often they're not. But why not pre-foreclosures? Why not distress situations? Why not probate and estate sales?
And, having said all that, I also agree with Pam. Yes, it is possible to "flip" houses today, but you have to be a lot more careful. You have to know what you're doing. And you have to buy even lower than in the past. (Thus my suggestion that you broaden your search, if that's what you've decided to do.)
Hope that helps.