Probably the biggest trap to fall into is to load your website with every graphic and technical trick you know about. The one BIG goal here - make sure your pages load as fast as possible. You should ensure that any page loads within 10 seconds. I have seen many sites where I am struggling to pay them my money - but cannot find an email address, an order page, any pricing, etc. Many people do not put email addresses on web pages as they fear getting SPAM emails.
Some sites hide their prices.
Either they want to sell something, or they don't. If they don't want to tell me the price of their product, then I will look elsewhere. If you are going to put up your own website, then do some homework. Get some tips on style and marketing techniques. List your website with search engines regularly.