If you are planning to buy or sell a home, it is recommended that you hire a certified home inspector to conduct the inspection. This is one way to learn the condition of the home and potentially gain more negotiating power during the sale/purchase of the home.
When touring a home, pay attention to anything that seems strange as it might be a red flag. Take note of any visible damage as well, as it might not be a problem now but it could turn into an expensive fix later.