SharePoint 2010 Master Page not getting deployed

If you copy a master page into your 2010 project and it's not showing up in your master page gallery, make sure in the elements.xml file you have the type as "GhostableInLibrary", like such:

<File Path="Intranet2010.master" Url="Intranet2010.master" Type="GhostableInLibrary" IgnoreIfAlreadyExists="FALSE" />

SharePoint 404 Resource Not Found Error

If you encounter a 404 "Resource Not Found" Error in MOSS 2007 you can View Source from your browser and at the very bottom (in HTML comments), will be the stack trace, which should lead you to the source of your error.