iippo: if you want mutations - skaven can be considered for newbie. and chaos dwarves (might be getting lots of those though). but forget about vanilla chaos, they are one of the most unforgiving teams for newbie. Nurgle is pretty much the same.
Humans, amazons, norse, orcs, undead - those are pretty solid to start with.
mefet: The problem with Skavens is their low av. They're great if you don't get nervous seeing how you nearly always have less players than your opponent.
I think humans and orcs are better for a newbie, but chaos is pretty solid. I mean is not like you're going to lose a lot of players because of mistakes...
err no. chaos is -NOT- solid.
Totally no skills. Unless you 100% understand the odds of dodging, block assists, what skills you need in what order, builds that make sense etc you will be quickly getting turnovers and get frustrated.
The thing with skaven is that they are fast. silly fast. so when you get the ball, its pretty easy to move it around the pitch and even score, for a newbie. also skaven have decent amount of skills, can try passing with very decent chance, are affordable and can buy good number of rerolls as well.
of the elfy teams high elves / de are the most durable, but especially DE are among the most expensive teams in the game so if/when you get really hurt - well it may be difficult to get back in game and not feel like a cripple.