NUMBER 1
Never sign a contract until you understand and are completely happy with the detail contained with in it.Do not fall for the Limited time offers etc that are designed to make you feel like you must sign right now.
NUMBER 2
Never, ever pay a deposit (or any other money) until the Builder has supplied you with a certificate of home warranty insurance with your details and the project location listed on it, if unsure ring the insurer to check its Validity. (By Law they must provide it for jobs over $20000 in NSW and $12000 in the ACT For any residential project being council approved and it must be provided to council before they will issue a occupation certificate)
And the most important thing to remember, you must feel comfortable with the builder you choose as it is a partnership to create what you desire .
Know Your Bulider