Here is some info about tfs sdk for TeamFoundation.
http://geekswithblogs.net/TarunArora/archive/2011/06/18/tfs-2010-sdk-connecting-to-tfs-2010-programmaticallyndashpart-1.aspx
I'd like to create project within selected collection in TFS using my own script. Unfortunately I can't find any decent documentation :/ I've already managed to create Collection from .net script using instance of ITeamProjectCollectionService and method QueueCreateCollection(). I believe there is an option to create project as well somewhere in this SDK. Has any of you worked with this SDK?