Drop-down menus in SharePoint enable actions that relate to a specific document in a document library. This article shows how these document context menus can be extended to add custom menu items.
Extensive article about visual mapping and information architecture in SharePoint environments.
All icons and images neatly categorized and sorted. Handy for dashboards or other occasions where you might need an icon to beautify things.
Extensive MSDN articles on branding and customizing SharePoint.
Nice little script that disables items in the Actions menu of a list or library.
Ten usage proposals for SharePoint in a law firm, all of them also applicable to other sectors.
Very comprehensive first part of an article series focussed on stylesheets and what you can do with them in a SharePoint environment.
Update: Here are the other parts: