I started with Poser 7 and Vue 6 in 2007. So many sites have come and gone since then. Don't really know which are relevant for a beginner in 2017. What I did was to buy a book for each one, to learn the basics. After that I looked for tutorials when I wanted to learn how to do something.
I have no experience with 3DS Max and I haven't got Poser 11 Pro, still using Poser Pro 2014.
Resources can be bought at places like Renderosity, Content Paradise, Hivewire, Vanishing Point, Renderotica ... and many more. Many of them also offer a lot of free stuff. ShareCG has a lot of free stuff. The new stuff at DAZ3D isn't really Poser compatible anymore and it's expensive too.