I keep a GC folder in my Favorites full of links to articles and blog posts about the .NET GC. I thought it would be a good idea to consolidate them all into one blog post, for handy reference. These are the articles I most often post as answers to questions on public newsgroups.
If you know of any other good ones, please post them in the comments! If you find some totally erroneous articles, point them out too.
GC Overview and Best Practices:
Garbage Collection (parts 1 & 2): Automatic Memory Management in the Microsoft .NET Framework
Implementing Finalize and Dispose to Clean Up Unmanaged Resources
.NET Framework General Reference
Turning off the garbage collector
Garbage Collector Basics and Performance Hints
Improving .NET Application Performance and Scalability: Chapter 5 — Improving Managed Code Performance
J.D. Meier, Srinath Vasireddy, Ashish Babbar, Rico Mariani, and Alex Mackman
Two things to avoid for better memory usage
Using GC Efficiently - Parts 1 & 2
Edit: Added link to Maoni's GC posts.