Here's a tutorial:
http://home.arcor.de/chiptuner/tutorial_famitracker.pdf
It's for a older version tho, so parts of it might be incorrect.
That's all I can offer, really. Poke around in the tracker, read LOADS of threads in the forum, and have a look at other peoples FTM files. You can find .FTM files here:
http://2a03.free.fr/?p=pub&type=ftm