From Katrien De Graeve blog a list of resources and tools for WSS 3.0 and MOSS 2007, she divided into topics such as:
- SDKs and development tools
- Development helpers and add-ins for WSS and MOSS 2007
- Tools for WSS and MOSS 2007 (object browsers, CAML tools)
- Add-ons to site settings and central administration
- WCM tools and add-ons
- SharePoint Designer 2007 tools and resources
You can fin this list here.