<a href="http://www.sharepointblogs.com/bmixon/" target="_blank">Bob Mixon</a> has a great list of references.  He's right, there aren't many formal sites/books out there worth buying... bloggers are the best resource in my mind (many are listed in my <a title="" href="http://www.microsoft.com/office/sharepoint/prodinfo/overview.mspx">SharePoint</a> links).
    <p>» <a href="http://www.sharepointblogs.com/bmixon/archive/2004/07/26/662.aspx" target="_blank">SharePoint - How Do I Learn?</a></p>