As far as boards most suitable for first timers, there seems to be 3 tiers now since the sx350 upgrades.
Tier1 includes the Vomo, Zmax, and Vamo. They're the 15 watters in the range of $12-25 USD. Of the 3 I'd suggest the Vomo (if you're comfortable with clone) or Vamo. The Zmax is a single button board, and is a pain to use in my opinion.
Tier2 is the DNA30, in the $50-60 USD range (depending on if you choose USB charger and which you choose) It is plenty of chip for most people, and if you want to build a mod in the moderate price range it's a good choice.
Top tier is now the SX350. It's around $75 USD, and is the best you'll find right now of the easy to assemble boards.The only issues with it are the YH logo on startup if it bothers you ( this will likely be changeable in the future) And it is (at the moment) slightly less available. (This of course changes day to day, since Yihi can pump out the chips)