This is my list of links to threads, articles, posts, and anything else I consider useful for developing with .NET. I'll try to mark things to indicate what language they use, but honestly VB and C# are interchangable. I'm not going to bother obsessively categorizing these; your browser has a search function and it should lead you to the links you need.

Asynchronous Programming

Loading data and displaying progress in an MDI Child form ( example project )

File I/O

MikeJ's File I/O Tutorial -- An introduction to text file I/O in .NET. At least half of the, "How do I do this with a file?" questions on the forum are answered here.
Using an ANSI encoding with a specific code page -- This one also contains a brief discussion of ASCII vs. ANSI vs. Unicode and how one might determine which encoding a file is using if you can't seem to get the I/O classes to read it properly.
Using random access I/O to read bytes at a particular offset in a file. -- Uses a general-purpose function to solve the larger problem; interesting in that it doesn't require random access to operate, though it's more efficient if it is supported.

General

Creating a file association
Creating a Windows Service in Visual Studio Express Edition -- VS Express Editions don't have the "Windows Service" project template. You don't need it. This is another "Visual Studio is not magic" topic.
The difference between value and reference types. -- Everyone should read this. Several times. I see new programmers tripped up by this about once every other week.
Why strings behave like both value types and reference types. -- Also explained in the above post, but jo0ls outdid himself with nice ASCII diagrams to illustrate. I describe value and reference types with respect to C/C++ pointers in a later response.
Painful errors that could have been prevented by Option Strict. (1 2)
Basic events tutorial -- Starts with the Observer pattern, explains delegates, then ties it all together to describe .NET events.
Intermediate events tutorial -- Describes best practices for imlpementing events in your types.
Advanced events tutorial -- Covers implementing advanced events. Can provide more robust performance and a better memory profile for classes with many events.
Plugins -- Discusses pitfalls and best practices concerning implementing application plugins, and includes a demo project.

Visual Studio

Converting VS 2008 projects and solutions to the VS 2005 format

Web

Loading HTML into an mshtml.HTMLDocument for parsing.

Windows Forms

Accessing controls from worker threads in .NET -- If you're using worker threads in a Windows Forms application, you need to read this to learn how to avoid the exception that is thrown when you make illegal cross-thread calls. I cover a new .NET 2.0 method for managing this that may or may not be a good idea.
Anchor, Dock, and layout panels in Windows Forms -- Discusses the effects of the Anchor and Dock properties on WinForms controls and how layout panels like TableLayoutPanel can help you create form layouts that look good as they are resized.
CheckedListBox demystified -- This post explains the methods and properties that are used to get values and item states from a CheckedListBox I hate this control and I feel like it doesn't add enough value to justify its complexity, but a lot of people seem to like it so here you go.
Determining the location of a mouse click -- Actually, this covers a method for always finding the location of the mouse. Bonus discussion of client coordinates vs. screen coordinates.
Filtering ListBox items based on user input. (project)
How to get the selected item from a ComboBox (VB) -- Includes property-by-property discussion. Mostly works great for ListBox too.
Iceplug's Control Arrays in .NET tutorial
Iceplug's Backbuffers tutorial (VB) -- Demonstrates GDI+ double buffering. Not made entirely obsolete by .NET 2.0's OptimizedDoubleBuffer property as this is still the only way to reduce flicker in certain cases.
Creating Transparent Controls in Windows Forms -- This is more difficult than you think, because GDI didn't initially support "layered" windows, which meant if controls overlapped you'd see your form's background color, rather than the control under yours. Using the layered window support added in Win2K, you can make controls that support better transparency. (WPF is the only non-hacky way to do it, though.)
ListView virtual mode -- This is a neat way to reduce flicker in a ListView when you're adding a lot of items at once. It doesn't seem to do true virtualization, but it can help.

XML

Parsing XML in the .NET Framework -- I outline the differences between two XML parsing approaches and provide a simple example using both methods.

The color scheme is "Subtlety of Hue the Spa" by wi.hi.fi at Adobe Kuler. Neat tool for finding colors if you're artistically disabled like me.