Here is a collection of some resources that I consider to be invaluable to those learning x86 assembly programming in a 32-bit windows environment.
Most of the following are free resources, however for those that are not, they are good resources, consider it your duty to acquire them legally.

x86 Assembly Language Webring
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Tools - You won't get far without these ;)(Confused? Skip ahead...) MASM - Microsoft's offerings, They argue this is still supported. This or the next, your choice.
Hutch's Masm32 package- 32bit Macro Assembler compatible with Microsoft's ML.exe supplied with VC
NASM - The famous Netwide Assembler
YASM - Homepage of YASM & Libyasm, The modular assembler project
TASM - Borland's Turbo assembler.
NBASM - NewBasic Assembler for DOS. Near compatible with MASM 5.1
FASM - Flat Assembler, a relatively new entry
Emu8086 - A very good emulator/assembler, especially for beginners. Definitly worth whatever they charge you now
Alink - Alink linker, needed for linking object files & libaries. A must if you don't already have one. Note a linker is packaged with both Masm32 & VC(a dependancy for MASM).
OllyDbg - An excellent debugger, definitely the best you can get without parting with any money.
IDA Pro disassembler & debugger - An expensive bit of kit, has a good reputation, although haven't used it myself. There is a freeware version floating about although it is no longer hosted by them.
RadAsm IDE - A very good IDE with syntax highlighting for many flavours of assembly as well as some HLLs.
NasmIDE - NasmIDE and NasmEdit, download them here.

Tutorials - Next port of call: get to grips with assembly Quick guide to the basics - Confused by that? Read my quick guide to the basics
Art of (HL)Assembly (dos/win/linux) - If you only read one book/tutorial on assembly, make this it.
PC assembly tutorial - A lower level alternative to AoA, NASM syntax
General look at assembly languages - A general and detailed examination of assembly language.
Wikibook:x86 Assembly - As of now 25% complete, has a good comparison of some different assemblers if you're spoilt for choice.
(16-bit)Assembly Tutorial - I've included this because of its concise introduction to some of the theory behind assembly programming.
Assembly Language Tutor - Nice introductory text, TASM syntax
Gavin's Guide to x86 Assembly - Well structured guide, TASM syntax, covers DOS interrupts nicely
Assembly Lab - Paul Hsieh's Assembly Lab

Microsoft Specific - Want to learn to use the Win API? Microsofts' Platform SDK - Useful Development Kit for anyone using the windows API, contains invaluable documentation and libaries
Iczelion's Win32 Assembly Tutorials - No doubt the best tutorials on the subject. Bookmark it. Twice.
Win32 Assembler Coding Tutorial - 5 part tutorial, examples included. NASM alternative to above.
Win32NASM - Samples, include files and tools for Win32 programming with NASM
Windows DDK - Driver development kit for windows
Windows API reference - MSDN online reference
Win32 NASM Tutorial - Short tutorial, NASM syntax

Furthur Reading/References - What next? AMD Technical Documents - Documantation for AMD processes/chipsets
Intel 64/IA32 Developers Manuals - Straight from the dragons mouth, know your environment
Reversing:Secrets of Reverse Engineering(book) by Eldad Eilam - With malware an increasing issue, RE is as always a useful skill
Reversing School - Nice 4 part lessons by eT
Introduction to Reverse Engineering - 12 chapters introducting RE.
AsmSource - Need inspiration? Loads of examples here
More examples - Few more Win32 examples, using MASM.
Even more examples - Learn by example.
AsmCommunity - Need help? Want to join/start a project?
LANAKI's Crypto Lessons - Classical cryptography course by Lanaki

You've reached the bottom. So, you think you've learnt x86 assembly?

Prove yourself wrong.