[publications]
[RFCs 2045, 2046 and 2047]
I find little of interest in the comp.mail.mime FAQ; it's aimed at possessors of broken e-mail clients.
"A Technical Overview of MIME" from Web Developer's Journal Archives.
[info on handlers in Tcl, Perl, Python, ...]
[printed-quotable vs. base64]
[MIME link page]
[not just e-mail--applied in HTTP, ...]
[Explain products' uses ...]