I have a simple Web site that uses HTML. Is there a good tool to help me manage this kind of web site?
Yes. There are tools available. Most of your Web hosting sites like GoDaddy.com, Network Solutions, Verio and the others have tools available to build some OK web sites. These tools have limitations but for basic sites they can do a good job.
Most of these web hosting sites also make available Word Press sites. Word Press is a fairly simple to use tool that can build some impressive web sites. Weebly.com is a web hosting site that also provides web tools. You do not need to know anything about HTML.
I think Sierra Stages uses Weebly to host their site. If you really want to be adventuresome there are two tools called Kompozer.com spelled KOMPOZER.com and COFFEECUP.com. These tools allow you to edit and build some very simple and complex web sites giving you an HTML editor that provides visual reflection of the site.
If you inherit an old web site in HTML these tools can make the maintenance of HTML a lot easier. coffeecup.com weebly.com Kompozer.com