The time you enjoy wasting is not wasted time.
FreeTDS is a cooperative, volunteer effort. Flame wars on the list are unknown and the signal to noise ratio is pretty high for its venue. Many people have contributed patches, and few have been turned away.
We don't have enough non-English speakers to test our character set conversion features. Anyone willing to participate in that way would be most welcome.
Canonical examples of using the each library would be very helpful to newcomers.
An isql Perl and PHP would all make debugging and testing easier for everyone.
Good patches are nearly always applied in short order. Patches uploaded to SourceForge trigger automatic notification to the FreeTDS mailing list.
Any corrections or suggestions, be they typographical, grammatical, structural, factual, or mineral are most welcome. Please send it to the FreeTDS mailing list.
The User Guide is maintained in SGML DocBook format; the file in your distibution is doc/userguide.sgml. It is a flat ASCII file that you can edit with any text editor. You don't have to know SGML to correct or add to the User Guide, however. Just open it up, find the place you're interested in, and type away. Do a diff -u old_version your_version and post your patch to the SourceForge site. Any errors or lackings in your markup will be graciously emended by yours truly.
We have just begun an independent reference manual to FreeTDS; the main API documents are the work of the server vendors. We're using Doxygen, which extracts documentation directly from comments in the source code, and we're maybe 25% done.
The TDS protocol is partly documented, as are the APIs to libtds and DB-Library, but much remains.