File in the misc tips category.
When typing a class name that is not in “using” scope yet, just start type the name and hit Ctrl+. (dot). You get a context list and can select the namespace to add a Using statement and keep going.
Example:
private AutoResetEvent(ctrl+.) // Select the "using System.Threading" namespace and keep going.
There is a Visual Studio add-in called ReSharper from JetBrains. If you really care about making your life easier while programming, invest in a license. If I type something and I don’t have a reference to it, it will tell me and all I have to do is hit the ‘tab’ key and it adds it.
If you are a student, you can qualify for a significantly discounted license.
Aside from that, you can probably just go on Stack Overflow and find this stuff out instead of creating a new thread. This way if you find something you like and post it on Stack Overflow, everyone can learn about it and not just this little community.
And what I really like, is the conditionnal breakpoint: you can set it by right clicking on the breakpoint indicator (red dot). And it’s support Intellisense too!