You should accurately and completely describe any products that you promote or sell. Online customers expect to see photos, prices, detailed descriptions, reviews, and any other product literature that is available.
You should also accurately and completely describe any services that you promote or offer. Make a list of all of your services and proceed to write paragraphs about each of them.
If you have already completed projects for other clients, they should be featured as examples of what kind of work you do, types of clients you work with, and what prospects can expect upon completion of their projects.
If you have a standard price list or chart, publish it on its own page so prospective clients/customers can compare your prices with your competition. Internet consumers like to shop around and if you don't list your prices, they will assume that they are expensive.
Subscription forms are an easy way to increase your exposure if you publish a newspaper, magazine, newsletter, or send out mailings. Your website can collect the names of people who are ALREADY INTERESTED in the content of your website and what you have to say. When mailings go out, these subsribers are more likely to become return customers than your average traffic.