XNA Creators Club
Official community created by Microsoft where developers of XNA (framework for game development) can share experiences, create and view tutorials and publish their games. Especially useful for people who never created games and want to do it.
DropBox
Dropbox is a service for file storage based on the concept of cloud computing. Powerful for file sharing in a group or just between computers used by the same user. Similar to SVN tools, but much easier to use.
MSDN - Microsoft Developer Network
Microsoft´s official site for developers of the Visual Studio tools. There you will find tutorials on various programming languages, information about libraries and discussion forums on various Microsoft technologies.
TED - Ideas Worth Spreading
TED (Technology, Entertainment and Design) is a foundation that organizes conferences various topics such as education, health, technology, economics and sustainability, making them available on its website in the form of small videos up to 20min.
DevTuts
DevTuts is a brazilian website which provides tutorials and video-tutorials about game-design and programming using the Microsoft XNA Framework and Adobe Flash, specially usefull for beginners.
Mozilla Prism
Prism is an application that lets users take web applications out of their browser and run them directly on their desktop. It can be used in Windows, Mac or Linux.
Pixlr
Online image edition freeware system much alike Adobe Photoshop, with many tools and filters. Very easy to use.