Building a house is no easy task. From surveying the building site to obtaining the necessary permits, it is tedious process. This is why you need an experienced contractor and not one who is going to learn the process on the job. After all, this is going to be your home and you do not want a shoddy job done on it. Getting a cheap contractor may seem appealing at first, but consider that you may find some unwelcome surprises a few months after you move in (like cracks, leaks, etc.).
1. Look up listings for contractors in your county or state. Choose three or four who have been in business for a while. Longevity is an indicator that they do decent work.
2. Get a minimum of three estimates and while you are doing that ensure that they have license to operate in your area.
3. Check up on them. Get references from the contractors and talk to those people. You should also put the word around with friends and family and see what they can dig up on the contractors.
4. Go over the contract carefully. Then, go over it with your lawyer. You need to know exactly what you are getting into. Sometimes you might want to include penalty clauses, so that the job does not take longer than it has to.
These are few general things you should look into when you are about to embark on a home building experience. This is one instance where it is definitely better to be safe and paranoid rather than have a disastrous home handed to you at the end of the construction phase.