Reading on the web is not the same as reading in print. It's better to avoid long passages of text unless you clearly indicate that this is a detailed explanation of something. In that case, you warn people beforehand of what they are getting into or offer the information as a downloadable file, PDF for example. Make your site easy to use. Consider some usability tests with a focus group.
Some people are capable of building their own sites but others prefer to use professional designers.
The best sites are still designed by those with a deep understanding of HTML specifications and limitations. If you don't maybe the web site should be contracted out as well. Issue a press release. A special announcement to all existing clients. This can be the focus of a sales call, if appropriate.