For games? Grab XNA and start messing around.
For software? Create a WinForms or WPF project and start messing around.
For websites? Create an ASP.NET project and start messing around.
Honestly, Sir Source, I don't know the best "starting C#" resources since I started C# after I was already proficient in C++, but the best way to learn is to !@#$% up, mess around, and learn what
not to do.
![Cheesy :D](http://zfgc.com/forum/Smileys/tplink/cheesy.gif)
XNA, in particular, is a great place to start. Poke around (well-documented) source code, come up with an idea, break it down into the individual components you'll need and start learning to build them all individually, and learn to tie them together. Or something. It's really cold, and I can't formulate thoughts very well. ;-;