1. StackOverflow.com My favorite website for random programming questions, or very specific how do you do that kind of questions, covers every languages. There are a lot of helpful comments and people willing to help you solve a problem.
2. Microsoft Developer’s Network (MSDN) contains a lot of technical information and Microsoft centric developer’s resources.
3. CodeProject.com Lots of well written tutorial and examples to show you how to do things in C# etc, provides step by step instructions to build a simple project, to help you better understand programming concept and usage.
4. Source Forge.net A very nice hosting service for hosting many open-source projects. Here you can join active projects in discussion and participate in contributing to open source projects.
5. Reddit Programming A list of great topics and discussion on programming etc