Assembly Language for Intel-Based Computers
Book by Kip R. Irvine. Printable chapters, reviews, corrections, Frequently Asked Questions, files, supplemental articles, updates to example programs.
Assembly Language Step-by-step
Book by Jeff Duntemann. Errata. Downloads.
Learn Microsoft Assembler in a Day
Online book by Stephen Cunningham.
PC Assembly Language
An online book by Dr. Paul Carter. It has extensive coverage of interfacing assembly and C code. All the examples use the free NASM (Netwide) assembler. The tutorial only covers programming under 32-bit protected mode and requires a 32-bit protected mode compiler.
Programming from the Ground Up
By Jonathan Bartlett is an introduction to programming using assembly language. It starts with nothing, and gradually introduces you to the basics of assembly language and computer programming.
The Art of Assembly Language Programming
Online book by Randall Hyde. It's available in three editions: a 32-bit edition for Windows, a 32-bit edition for Linux, and a 16-bit edition for DOS.