I took the Advanced Design VMware NSX-T 3.0 Exam recently and these are the study links I used:

NOTE: Understanding the last 2 blog posts is essential to being effective in this exam.

NOTE: Digging into customizing NSX-T for NFV has value also.

NOTE: If you only have time to read one PDF, then the NSX-T 3.0 Reference Design Guide is the one to focus upon.