SourceForge
The World's Largest Open Source Repository.
ASM Community
"The" Assembly Language Resource.
The NASMX Project
Enhanced NASM Development Kit.
Paul Carter's Tutorial
Introduction to 32-bit Assembly - NASM Syntax.
LinuxAssembly
Information about using NASM with GNU/Linux and BSD systems.
Ralf Brown's Interrupt List
Every documented/undocumented interrupt call known in a single list.
DynatOS
An Operating System project with an x86 kernel designed purely in NASM.