I'm checking out the FAT32 spec right now, and am interested in NTFS. But...
According to wiki and some other google links, the NTFS specification is a "trade secret" and Microsoft hasn't released any specification to the public.
However, it exists and can be easily experimented on and manipulated with any Win2000+ machine. Does anyone know of an unofficial release, or at least a hack specification compiled by an individual or something?