You need a home inspector. When you hire a home inspector, you are hiring an experienced professional who has training and experience in the building industry. It is the job of the home inspector to not only evaluate the condition of the house's major systems and structural integrity, but also to evaluate how these systems are working together and identify areas that need to be watched, repaired or replaced.
That said, it's very important you realize the inspector is working for you and not a third party. Question: If the inspection is preset by a real estate agent, who's the inspector really working for? The agent who is working for a commision, or you. You're paying the inspection fee.
Real estate agencies should provide you with a list of local home inspectors. Many times they will recommend a inspector which is fine. But you should make the decision on who is eventially going to inspect the home. If a inspector is recommended, call him and ask questions. Look up his web site. Get a feel for his personality and determine if he is the right fit. Don't ever allow a real estate agent to schedule the home inspection without your knowledge.
Remember the information provided by the inspector is a important component in the buying and listing process and should help you make educated decisions. I would hope it is also a positive experience.