There are loads of directories you could consider joining, all of which are online and most of which are free. Mutual linking with other, closely related sites. The internet is an informal and vibrant community of people who want more exposure. If you offer them that through a link to their site, they are usually more than happy to put a link to your site in return. Search engines rank their listings by the number of links a site has - another good reason to get widely linked.
Content is king on the internet.
If you want visitors to return to your site, you'll need to give them good reason to come back. Updating your site once a month with new information or services is about the only way to ensure visitors become repeat visitors. Also, you'll need to let visitors know when the site is updated. The best way to do so is probably an e-mail list to which they can subscribe for more information as it becomes available. This can be set up by your webmaster or by yourself if you know the nuts and bolts of file transfer protocols and CGI programming.