Foreclosure Information that is useful and necessary to investors

I am wondering what investors looking into foreclosures are looking for in the data they are receiving. For example, do you mainly search out data from title companies? Real estate agents? Online databases? What information would you think is absolutely necessary (like owner name, address, attorney info, property details, loan information, etc.)? Is it important to know when and if a property sold at auction or do you not really use that information?

Also, with the deflated real estate market right now, is investing still a good market? Are people really finding success in investing in real estate right now? What about in foreclosures?

How do you get a property owners info after they have defaulted on loan? Does the lender file with the county the property resides?

Name, address, Lis Pens date at the least. Mortgage amount is nice, but im not too sure can be deemed accurate b/c theyre may be other liens on the property. Zestimate or town assessment could help too so your not mailing anything over your price range.