First off let me start by saying. I know there are about one thousand of these out on the net. This is just my personal list. The site and resources I personally use the most. So when starting to delv into SharePoint (MOSS 2007) development here is a list to start from.
First of all, MOSS is totally built on ASP.NET 2.0 a good foundation is important, these links are a good place to start.
ASP.NET:http://www.asp.net is a great resource for learning the power and capabilities of ASP.NET. How Do I: Use Master Pages and Site Navigation?http://www.asp.net/learn/videos/view.aspx?tabid=63&id=9http://www.asp.net/learn/videos/view.aspx?tabid=63&id=48How Do I: Customize my Site with Profiles and Themes?http://www.asp.net/learn/videos/view.aspx?tabid=63&id=44How Do I: Utilize Web Parts and Personalization?http://www.asp.net/learn/videos/view.aspx?tabid=63&id=43How Do I: Learn the Tips and Tricks of Experts?http://www.asp.net/learn/videos/view.aspx?tabid=63&id=39
SharePoint Resources:The main informational Microsoft Office SharePoint Server 2007 Pagehttp://office.microsoft.com/en-us/sharepointserver/FX100492001033.aspxSharePoint Resources on TechNethttp://www.microsoft.com/technet/windowsserver/sharepoint/default.mspxSharePoint on MSDN (This is one of the site I use the most.)http://msdn2.microsoft.com/en-us/sharepoint/default.aspxWindows SharePoint Services 3.0 SDKhttp://msdn2.microsoft.com/en-us/library/ms441339.aspxCreating a basic SharePoint Web Parthttp://msdn2.microsoft.com/en-us/library/ms452873.aspx
Screencasts - http://msdn2.microsoft.com/en-us/office/aa905382.aspxCreating a Custom Page Layout with SharePoint Server 2007http://go.microsoft.com/?linkid=5519356Building ASP.NET Web Parts for Windows SharePoint Services 3.0http://go.microsoft.com/?linkid=5519355Creating and Testing Features with Windows SharePoint Services 3.0http://go.microsoft.com/?linkid=5519357Creating and Using Event Handlers in Windows SharePoint Services 3.0http://go.microsoft.com/?linkid=5519359Creating Custom Workflows with the SharePoint Designer 2007http://go.microsoft.com/?linkid=5519363Customizing a Windows SharePoint Services 3.0 site with the SharePoint Designer 2007http://go.microsoft.com/?linkid=5519365Generating Office Documents using the New Open XML File Formatshttp://go.microsoft.com/?linkid=5519369
Newsgroups:SharePoint - General Q&A and Discussionhttp://www.microsoft.com/communities/newsgroups/en-us/default.aspx?dg=microsoft.public.sharepoint.general&lang=en&cr=usSharePoint - Setup and Administrationhttp://www.microsoft.com/communities/newsgroups/en-us/default.aspx?dg=microsoft.public.sharepoint.setup_and_administration&lang=en&cr=usSharePoint - Design and Customizationhttp://www.microsoft.com/communities/newsgroups/en-us/default.aspx?dg=microsoft.public.sharepoint.design_and_customization&lang=en&cr=usSharePoint - Development and Programminghttp://www.microsoft.com/communities/newsgroups/en-us/default.aspx?dg=microsoft.public.sharepoint.development_and_programming&lang=en&cr=us
BLOGS:Stefan Goßnerhttp://blogs.technet.com/stefan_gossner/Andrew Connellhttp://andrewconnell.com/blog/Arpan Shahhttp://blogs.msdn.com/arpans/Mei Yinghttp://meiyinglim.blogspot.com/Todd Baginskihttp://www.sharepointblogs.com/tbaginski/Dan Larsonhttp://daniellarson.spaces.live.com/Joel Olesonhttp://blogs.msdn.com/joelo/