Although I'd love to do a whole set of guide entries focused on NinjaGo, it doesn't seem to be in the cards right now. No worries, however, as Eurobricks has a nice collection of set reviews.
One of those reviews showed off a character list (pictured above) of the key players in the NinjaGo universe. Note 'Chopov' and what appears to be a black pot helmet from the Toy Story soldiers. Other baddies of note are 'Garmadon' and the four-armed 'Samukai'.
These designs are very much in the style of Mike Rayhawk, who has done designs for LEGO in the past. I believe Mike is a reader of the site, so hopefully he can talk about his involvement with these sets (or at least let us know if the card art is his!)
Check out the collected reviews on Eurobricks and start planning which sets you'll purchase today. Officially, these are set to go on sale January 1st, but I've heard a few sets have made their way onto shelves a little early.