I'm in need of an archive or file which describes the various ROM image formats used by the copiers for NES, SNES, etc (hopefully in an articulate manner!). Any help would be appreciated! :)

iNES is the most common NES format, here's some docs:
http://nesdev.parodius.com/iNES.txt
http://nesdev.parodius.com/neshdr20.txt

There is also a UNIF format, and a couple more formats you probably won't see anymore. (pasofami and famtasia)

As far as SNES, I dunno. Sometimes it's just a plain copy of the ROM (when smaller than 1Mbyte), but often they have a 512-byte header.

You can find details as to the SMC/SWC 512-byte header here:

http://cgfm2.emuviews.com/txt/swcteche.txt

See Section 4, labelled "FILE HEADER".

NOTE: Most emulator and utility authors *HIGHLY* recommend ignoring Super Nintendo ROM file headers, and getting the proper information from the ROM image itself (since most of the information is kept in the ROM, excluding "multi-disk-spanned" ROM files). I believe the ZSNES and SNES9x authors both agree that the majority of SMC/SWC headers they encounter are incorrect anyways.

-- jdc