How To Sketchcast
Screen recording tools:
* Cam Studio (free)
* Krut Recorder (free)
* ACA Screen Recorder ($30)
* Camtasia Studio (full-featured and very powerful, but $300)
* And many, many others.
Drawing Tools. For drawing tools, you can pretty much use anything. I really enjoy using Artrage. It's only $25 and there's even a very capable free version. You can even use good ol' MS Paint or the free Paint.net.