To avoid a bad experience, make sure your sales contract includes an inspection contingency.
Your mission during the inspection period, is to learn as much about the property as you can. Investigate any issues that could affect whether or not the property will meet your long time needs.
Find out what systems need routine maintenance. Ask the seller to provide you with contact information of any people who have worked on the property that they would recommend.
Many states have property disclosure requirements. Illinois is one state that does. Make sure you get a copy. It is Illinois law that you do. Any problems that seller has had should be declared to you.
Sometimes the seller has had an inspection before putting the house on the market. Make sure that you also have your own inspection with someone that you have hired.
Today, many are purchasing REO (bank owned) properties. In this case you will receive little information from the seller. Be extra careful and investigate anything that you can.
Buying a home can be a good experience as long as you are careful.