Here is a great resource for NSX. The site Hypervizor.com by Hany Michael, a Consulting Architect at VMware. One of his recent posts covers the architecture of NSX v6.0. He also has some great videos on walking through the process of deploying and configuring the different NSX components. You can follow Hany on twitter @hany_michael.
Oh, and while you’re over there, check out his Visio templates.. they are awesome.