These are described in more detail and with more examples at the Ext.NET website:

http://examples.ext.net/

In particular, see the Layout section for more layout examples.

In addition, the documentation for Ext JS at the Sencha website provides further details and as the underlying JavaScript framework, is worth getting familiar with as it can help understand and appreciate what Ext.NET is doing for you. It can also help you troubleshoot any problems that may arise. This documentation can be found at:

http://docs.sencha.com/ext-js/

In particular, look for the documentation subsection on layouts.