For me the sorcecode works well with VisualStudio 2012 and the preview version of 2013. You should set up your Visual Studio with an english language to not clutter the automated generated code with other langues. I also have my Visual Studio with all updates up to date. Visual Studion 2010 I didn't reccomment because I think it has an incompatible solution file format. If you have an environment which can build and run wpf-projects it should open and compile without errors.
For getting the source code: Fork the project on github and install a git-environment (TortoiseGit, MyGit, Git is built in VS2013) and clone the repository of your githup-fork to your computer. EDUCATE yourselve on using git is realy nesesary for submitting pull-requests (asking for changes in your fork to be introduced to the official SambaPOS)