Hi Xorty
I would recommend anyone starting with SharePoint now to start with SharePoint 2010 Foundation.
The reason being that getting up to speed with SharePoint 2010 is a lot easier that SharePoint 2007 due to the tool support in Visual Studio 2010.
But before going into development mode you should learn what's possible with SharePoint out of the box, and using SharePoint Designer
When you've learned SP2010 with the help of the tools, then you should:
- look at what the tools gives you and learn how to manage these xml files yourself (maybe using WSPbuilder)
- learn what isn't available in WSS 3.0
- learn what is extra in MOSS 2007 and SPS 2010
Knowing .Net, C# and ASP.NET is the main things to give you a good platform for learning SharePoint other things which is useful, but can be learned along the way are:
- XML/XSLT
- PowerShell
- SQL Server
- SilverLight
- JavaScript/Ajax/JQuery
- Windows Workflow
- InfoPath
- ...