I would get some books as well as the basic training.
If you are using WSS 3.0 I can recommend Step by Step Microsoft Windows SharePoint Services by Bill English et al
If you are using WSS 3.0 with MOSS 2007 I can recommend SharePoint 2007 for Dummies by Vanessa Williams
There are a lot of SharePoint books on my shelf but these two are the easiest and best to get up to speed quickly.
It will help you to understand that this is a web browser based appliaction based on Microsoft IIS web server with data stored in an SQL database (Express version or SQL Server 200X)
It is easy for people to use SharePoint but also know that because it is based on several technologies it can be difficult to troubleshoot and supporting SharePoint requires a wide spread of knowledge