For Vox specific things, the user manual is helpful.
Download it from kobobooks.com as an ePUB (it is drm-free) and use the Calibre or Kobo desktop app for reference as you try things out on your Vox.
The rest is really an Android for Dummies kind of thing--and believe it or not there isn't one. I used
this guide on Andronica when I got my first Android phone. They have added lots of material since then.