Microsoft Virtual Labs
A relatively unknown service that Microsoft provides is that of virtual labs. If you use this link:
you will find 65 labs that you can sign up for and do free of charge. This labs are great because through your browser you can run a BizTalk server environment exactly as if you had a remote connection to the server. There are step-for-step manuals and all the source code is there as well. If you are curious about testing out some of this technology I high recommend giving them a try.