<p>How do you create a "dockable" form, similar to the windows in Visual Studio?</p>

I've used Weifen Luo's "DockPanel Suite" to good effect. It's an open source library that mimics Visual Studio's docking system very well, including nested docking, floating windows, tabbed windows, etc. You can download his source and see his approach there, if you'd prefer your own, simpler solution.
Sourceforge project here:
http://sourceforge.net/projects/dockpanelsuite