Giampiero Caprino's Home Page
Contains useful information about Decompilers and File Formats. Object Code Translation Home Page
Some introductory discussion of disassembly. Also has a glossary, and short description of file formats. Many links to other resources. COBOL missing source code recovery, disassembler - FAQs
A fairly detailed discussion of how one commercial disassembler works. Clive Turvey's Home Page
Source for a commercial disassembler and a selection of free downloads related to disassembly. Also has a useful collection of links to related sites.