You get out what you put in

I'm a frequent contributor to the Microsoft HPC forums (http://social.microsoft.com/Forums/en-US/category/windowshpc). There are diverse and interesting threads to follow, and from a completely selfish perspective I've found getting involved there to be an extremely useful learning experience. It's also not uncommon to have a question answered by a member of the HPC product group, who are obviously amongst the most knowledgeable people available.
Basically, if you're embarking on a journey into Windows HPC you can do worse than hang out there!