Contact your state dept of Consumer Affairs (or equivilient) as they often have tips for people building.
Check out this link
in contract terms etc.
Make sure you read the contract carefully - do not sign it straight away. Do not be afraid to ask any questions. THIS IS VERY IMPORTANT.
Make sure you have a liquidated damages clause in the contract - that is if the builder goes over time you are compensated. Builders often leave this blank or with 0 or nil. That means you get nada if they go over the building completion date. However, they will make sure they get compensated if the client causes any building delays.
Know your rights as a client. Make sure you understand the stages and progress of a build and how the billing works.
Check the specifications and drawings carefully. Make sure you know what the builder is doing. Find out what products and materials they are using and that you are happy with the quality.
Make sure you get a completion date in writing and if it gets close to that completion date and it does not look like the building will finish then, do something about it.
Avoid variations to the work - they are clostly. This is when you make changes to the building during thw work. The builder will charge a $$$$ profit margin. Too many variations can create major headaches with the accounting - make sure you get variations in writing and that you understand them. Be careful of paying cash in hand to any of the builder's tradies as some do this to avoid variations and if things go wrong, the builder will distance themselves from the tradies. If you make any cash in hand payments make a record of it. Do not do cash in hand variations.
Often what you are told at the sales pitch is different from what you will be told at the build stage. This can lead to lots of problems as what you may have been promised is not what you will get.
Ensure you have communcations to the builder in writing. Keep a diary of all things to do with the build. Keep a paper trail. Follow up everything. THIS IS VERY IMPORTANT.
If you can, visit the site and check progress against all the specifications etc. Measure and check everything you can to ensure it is up to expectations. Make sure you get certificates of compliance at all stages of the build and CHECK THEM thoroughly.
Have a lighting and electrical plan.
DO NOT PAY any progress payments unless you are completely happy with the work done and that the stage has been fully completed. THIS IS VERY IMPORTANT.
Get a building inspector when the work is done to check the work before the final inspection and final claim. It may cost money but it will probably be worth it. I WOULD RECOMMEND THIS STRONGLY.
You may end up with a difficult building manager who believes that the client is always wrong. Never let the building manager or supervisor intimidate you. Do not make on the spot decisions, think things through before you agree to anything.
Building is stressful. Dealing with builders can be very stressful.
If a builder says "trust me" don't believe them.