Get the Proposed Statement of Work in Writing
Once you are satisfied that you have narrowed the field of available candidates to just a few (say, three to five), discuss your site plans with each of them. Your initial meetings should cost you nothing except for the initial meeting with the developer who gets the bid; then plan to see that initial meeting as part of the work for which you are paying. Charges for the initial meeting are rarely applied by developers who do not win the work, but it is a good idea to ask if they charge.
Ask all your developer candidates to submit to you a written statement of work detailing all the tasks they will perform, the time frame within which they will act, the tasks and items they expect you to perform or provide, and the expected price for the job, including the expected price range and the conditions under which the price could vary, as well as a payment schedule. Half in advance and the balance within ten to thirty days of completion are typical payment terms.
Some Web developers offer a "per-page" price. I recommend against that approach because it encourages unnecessary squabbles over page-size issues. A Web page should be the size it needs to be to accomplish its purpose. Some pages are very long, while others cannot be more than a single screen high. Instead of the "per-page" pricing system, demand a per-hour approach, with an estimated range in total cost for the project. Most Web developers will offer a guaranteed fixed price for the project. Although a fixed price does reduce your risk, your Web developer will just bake a "risk margin" into the fixed price. If you are comfortable assuming some of the risk, you frequently can get a better deal with an "estimated price range" and a guaranteed "no higher than" price. Talk these issues over with each candidate; then make your own decision.