Trademark law links
Cornell Trademark Law Page - this is the trademark page within Cornell's Legal Information Institute with links to many of the national and international trademark laws. It also includes general information about trademarks and many other useful links.
Trademark Electronic Search System (TESS) - this is the USPTO basic search site.
Trademark Status & Document Retrieval (TSDR) - this is another USPTO site for more in depth searches.
Global Brand Database - this site is run by the World Intellectual Property Organization, and can be used for international trademark searches.
Trademark Manual Of Examining Procedure (TMEP) - The is created and updated by the USPTO, containing guidelines for USPTO attorneys and materials in the nature of information and interpretation, and outlines the procedures which USPTO attorneys are required or authorized to follow in the examination of trademark applications. Specifically, see section 1200 for Substantive Examination case law and analysis.