The FreeTDS mailing list archive is a good place to start. It is searchable. It should be considered the most up to date (and least edited) source of information.

New developments between releases tend not to be announced on the website. The website is updated only intermittently, when we post a new release or FreeTDS is somehow in the news, say. If you found a bug or need a feature, you may find it was announced/discussed/fixed by perusing the archive.

Many of the original authors and anyone maintaining or extending the code reads the list. The traffic tends to be bursty. It usually focuses on build problems and troubleshooting. Again, the more specific your question, the sooner you'll get a useful reply (if it comes).

Please, do not email the authors directly. You may well be ignored because they're they type that gets a ton of mail. Anyone willing to address your question reads the list, and you don't want to offend anyone willing to help you by going about it the wrong way.