Let me show you the ways.
Well more accurately let the article I just created tell you. You can find it here in the Supportweb Document Library as free download. The article takes a brief look at the different options and considerations you need to make before installing Sharepoint V3.0 onto a Small Business Server 2003.
If you don't already know then you shouldn't do an in-place upgrade (it breaks things if you do), you also have the option to install the Sharepoint into SQL if you want (although the "official" Microsoft procedure doesn't mention that).
The articles looks at the installation of Sharepoint V3.0 on SBS from a reseller or systems implementer's perspective, however hopefully this doesn't mean that it won't have value for other attempting this kind of installation. I also mention some of the benefits the Microsoft Search Server 2008 will bring to SMB space given its ability to not only index Sharepoint content but also file shares.
As always I appreciate any feedback on this article or any of the material that I create. Also, if you are interested in something specific them also let me know since I like to create material that is of benefit to "real" people.