The MSDN docs are almost essential to have installed. Use from the CDs w/o installation is nasty and dates to the days when hard drives were tiny.

These CDs contain a bunch of CHM and related Help files making up the documentation system, so there is no single file. I'd have to dig mine out but I think there are 3 CDs in the package.

You used to be able to order these and even subscribe to quarterly updates, but those days are long gone. The October 2001 edition was the "best" one for VB6: the newest edition before they began to rip out VB6 docs and samples.

None of these are marked "not for resale" and don't have any explicit restrictions on selling them but copying isn't allowed. You'd have to scout eBay and other "used software" sources for original media.