Windows API
Things like declarations (I know, you get them with VB, but hey), explanations, and introductions to the Win16 and Win32 API.
[>] contains a lot of API information for VB developers. They have a lot of source code and a fair set of tutorials, and provide a good resource.

The most important feature at is the API Guide. This excellent piece of software contains a searchable index of the entire API, with descriptions and examples for each function. A must-have if you regularly work with API calls.

[>] AndreaVB
An excellent site with lots of information. The content ranges from low level programming using the Windows API, to ASP and COM components. You might get a bit lost in the design, but focusing on the center white section of the page will help a lot.
[>] Brad's VB-32 Programs & Samples
A real top site. The source code available at Brad's reveals the downsides to Microsoft's common controls by taking them places you've only dreamed, and demonstrates a lot of API functions available.

The site is only updated at irregular intervals. This may discourage you from returning, but check in now and then to catch the few updates. It may be worth it.

[>] Edanmo's VB Page
This site is all about advanced source code.

The source code itself is outstanding -- VB source for custom controls you have dreamed about and system operations you've wanted to perform. On top of that, you get a bunch of free pre-compiled controls and time saving type libraries ready for use.

[>] FreeVBCode
This site is a large and well sorted collection of source code. The code pieces range from banal to excellent, and should satisfy all levels of expertise.
[>] Hardcore Visual Basic
[>] microsoft.public.vb.winapi
[>] microsoft.public.vb.winapi.networks
[>] Scrolling a text box
Have you ever wanted to be able to scroll a textbox automatically to the bottom each time you add some text? Here's how:
[>] Software Creations
A site that's off to a good start. The articles and code library are up and running, and contain some interesting items. A few points have been subtracted due to the very short descriptions of the various items.
[>] Spyworks
Spyworks from Desaware is a low-level system utility designed to intercept and let you act on Windows' messages. This enables VB programmers to add more power to their application, since they are no longer limited to handling the system events that VB traps.
[>] VB by JC
The author provides a small, but delicat set of articles and projects exploring advanced programming issues. The samples are well worth looking at just for the fun of exploration, and can serve you well if you are into this sort of problem.

With so few items, a search option would be inappropriate, and no points can be deducted on those grounds. The site is nice and well structured, so the only negative side is in fact quantitive.

[>] VB Web
An excellent site. The VB Web contains numerous tutorials on all flavours of Visual Basic development, with a vast source collection and well structured content.
[>] VB-2-The-Max
VB-2-The-Max is based around Francesco Balena, Italian VBPJ editor and regular VBITS speaker. The site is a tremendous resource for intermediate to advanced programmers, with lots of small tweaks and code samples you can utilize in your applications.

The site appears somewhat unstructured, but the search option remedies this in the usual way, so chances are good you will find any relevant items they have to offer you.

[>] VBnet
VBnet focuses mainly on using the Windows API from Visual Basic. The site includes tons and tons of code samples on how to perform any given task using API calls. You must be in serious trouble if you cannot find a solution at VBnet.

As part of VBnet's philosophy, the code isn't contained in downloadable form; rather, it's listed entirely in the article. Inconvenient if there is a lot of code to copy, but more convenient when you want to browse through it to get the general idea.

All in all, VBnet is one of the best code sites around, which is why it deserves the 4 star rating.

[>] Visual Basic 5.0 Programmer's Guide to the Win32 API
The fans of Daniel Appleman, knowing him from the legendary Visual Basic Programmer's Guide to the Windows API, get what they expected with this updated version of his API documentation. It is the Win32 API bible, looking at the internals of Windows with the VB programmer's glasses.
[>] Visual Basic Expert
At first glance, the site seems like a valuable resource site. Their book reviews are of high quality, and the information is nicely structured.

However, when you depart into the source code, you will find that it is only accessible by searching for it -- you cannot browse it. I find this to be an annoying limitation, although one might argue that the search function handles most visitors' need.

The source code itself is very good, and at present, the database contains 186 source items. This will improve in time, and make the Visual Basic Expert a quality site.

[>] Visual Basic Thunder
The site contains a lot of excellent source code relating to the Windows API. The code is well documented and illustrates dozens of useful procedures and methods. The downside is you can't search the site, so you are stuck with browsing the different categories to find the information you need.

Visual Basic Thunder is worth a visit if you want to check out new and cool ways to use the API with Visual Basic.

[>] Windows API Guide
Yet another API index. This site follows the standard set by Dan Appleman's various API books in describing and providing examples for every function and structure. The documentation is very good, but the maintainer has yet to cover all API functions.
[>] Windows Cryptography Overview
An overview of Microsoft's CryptoAPI with tools. This is a good reference, but it requires you to translate C type declarations to Visual Basic.