To make a successful website you need careful planning and thought. Deciding what you want from a site before getting a website built will also save time, money and reduce problems in the longer term. It is always best to start the design process with a clear idea of the purpose of the website. Try to provide the designer with some samples of similar sites and designs that you like.
Please note that many web designers will not accept a job unless the content has be created and site has been properly thought through.