Jachty
Jachty. Page by Primoz Peterlin with a main emphasis is on ISO 8859-2. It contains also a lot of useful links for Central and East European languages.
http://www.stocznia-jachtowa.biz.pl/jachty.htm

IBM code pages
Comprehensive list of code pages supported by IBM. Each code page is presented as a PDF.
http://www-1.ibm.com/servers/eserver/iseries/software/globalization/codepages.html

Windows Codepages
Provides links to graphical representations, and textual listings, of each of the Windows codepages.
http://www.microsoft.com/globaldev/reference/WinCP.asp