If you don't want to pay a Title company to do a lien search on the property (there are good title companies in Berks that will do a lien search for a real estate agent on a property that their buyers might be interested in, but they usually cost around $100 or so), there are companies online such as http://www.homeinfomax.com/ where you can pay a 1-month "subscription" fee of about $15 to check out 2 different addresses, and then pay for a Voluntary Liens report (which is probably around $15 also). This should give you most of the information needed regarding foreclosures, sheriff's sales, mortgage balances, etc. that you would need.
Best advice is probably talk to a real estate agent first - they can see the basic mortgage information, when the house was previously bought, etc. immediately for you in the public records to which they have access, then set up a showing on a property that you like, and THEN if you decide you're seriously interested in a house, you can always decide to pay for more information.