I've never tried visualsvn, but we use TortoiseSVN (http://tortoisesvn.net/downloads
) which seems to work well. We have plans to create a demonstration about how to connect to the svn repository and how to use TortoiseSVN, but for now a google search for a "tortoisesvn tutorial" should bring up some helpful results.
The \trunk\ will always contain the most up-to-date code and currently all the v0.6 code.
So, to get started with v0.6, you'll want to download just the \trunk\ folder. With that you will get the freshest code. Once downloaded, just double click on the Coolite.Toolkit.sln file within the root of \trunk\. Visual Studio will startup and you'll be able to "build" the current project. The main project of the Solution is "Coolite.Ext.Web". If the build compiles properly a fresh Coolite.Ext.Web.dll will be added to the project /bin/ folder. This is the .dll you can add to (or Reference) with any web projects where you want to use v0.6.
A "tag" is created for each public release which allows you to build any version during the project history. Currently within the \tags\ directory there should be 5 folders. One for each release from 0.5.0 --> 0.5.4.
Hope this helps.