I'm interested in knowing what resources you guys used to become advanced 3ds max users. What was most helpful? Professional video tutorials (digital tutors, lynda, etc)? The official documentation (http://help.autodesk.com/view/3DSMAX/2015/ENU/)? Books? I've learned Wall Worm through Shawn's videos and documentation to a point where I can get a level running in Source. Now I need to learn 3ds Max itself.
I've been a Max user for so long it's sometimes hard for me to answer honestly this question. In my case, there were a couple books I bought back in the later 1990s that helped me. Those books specifically would be of little value now. Back then the resources available on the Internet were nothing like what we have now.
I think that the best advice is to simply practice in the program as much as possible with specific tasks you want to accomplish. If you run up against a wall, then look in the documentation. If you cannot find an answer, then use good old Google. Also, you might make a habit of watching a video or two every day on the Autodesk Learning Channel (https://www.youtube.com/channel/UClS3gPxzFYgTUz6JOIruyqA). Each video will likely give you new ideas on using the features you never knew about or new ways to use those you already knew.
And of course utilize the various CG forums. I have personally learned a lot over the years from the Area (http://forums.autodesk.com/t5/3ds-max/ct-p/area-c1) and CG Society forums (http://forums.cgsociety.org/forumdisplay.php?f=6). I've always hoped to see more WW users also participating on general Max help on these WW forums, but that is currently hit or miss :)
Well, I'm still learning but if its of any help I've learned a lot from this guy www.3d-sphere.com (http://www.3d-sphere.com). I think he does a good job at making tuts for 3ds max noobs. All his tutorials are free so.. definable worth a look.