Home inspectors are a key part of any addition or remodeling process. They are the people who come out and inspect each phase of the project, to ensure compliance with building regulations and safety regulations. If you have earthquakes or floods, or some other form of natural disaster in your area, the home inspector will check to make sure that everything is up to code for those things as well.
A good home inspector can often be found by calling the local permitting office. The local office, where you got the permits, is also the office that has home inspectors. Whether you want a home inspector to inspect your own home, and tell you if something needs to be fixed, or to inspect a home you are thinking of buying, the local permitting office can often give you a list.
If you are using a real estate agent to purchase a house, they often have a home inspector they work with. There is no reason to feel obligated to use their inspector, but they probably have a good relationship with a reliable inspector, otherwise they would not continue to use that inspector.
Lastly, consider referrals. If you have a friend who has used an inspector recently, ask them if they were satisfied. There are also online services that rate home inspectors, just like other service professionals. If you are unsure about the inspector you are considering, ask for references and call the references.
Protect yourself when you are using a home inspector to get the best home inspector around. This is not a place where you want to cheat yourself.