There are two places you can find good coverage of NDIS.
1. Visit the Microsoft Developer's Network Web site and search on NDIS or "NDIS documentation."
2. Addison-Wesley has some great books on writing Windows drivers. You should also find ample coverage of NDIS in there.
If these two suggestions don't produce the desired results, I suggest you e-mail Microsoft's Developer's Network and ask them if they can sell or otherwise provide such documentation for you. If it weren't available, third-party companies wouldn't be able to create drivers for their network interfaces.
This was first published in April 2001