Learn web design. With Wordpress, Jumla!, and many online services you can quickly produce attractive web presences. For real power, but a larger learning curve, I love using Drupal. Drupal is the open-source (free) tool I use to design and maintain this Amherst Sax Quartet site.
As a start, click the Sax Quartet Links button on the left to view almost 100 other sax quartet sites. It should give you a good sense of what you like and don't like. [It may also help you avoid some cliches -- it seems that so many sax quartets claim to be the only ones doing what, it turns out, almost everyone else is also doing.]
Content is the most important thing, and with modern technology, producing video and audio, posting to your site, as well as YouTube, facebook, etc., is a great way to build an audience and share with colleagues. (If you already have a site and would like it to be included here in our 'Sax Quartet Links' section, just click HERE to send us your info.)
Also, don't forget to use 'age-appropriate' tools. For digital natives, the internet is everything, but your audience may include people who are more reachable by snail mail, phone, email lists, carrier pidgeon, etc..