A good set up really depends on what race you're playing and there's not really a comprehensive guide to setups and stuff. There is loads of good advice in individual blogs in the team development section but off the top of my head I can't give you specific links which is a shame. I can tell you what I try and think about when I set up and show you some of the ones I like. Also on offence it pays to set up according to how your opponent has so it's difficult to give you a cover all receiving formation.
With my High Elves on defence I have been setting up like this.
xxxx-xxLLLxx-xxxx
xxxx-xxxxxxx-xxxx
xxLx-xBxxxLx-xLxx
xLxx-TxxxxxB-xxLx
Sorry I know it looks terrible
But basically I like this formation for an agility team. Firstly there's no easy route through it. Secondly if it's at it's weakest, it's through the centre. If he does attack through the center I know most of players will be able to reach his receiving threats and be involved with defence. No defence is perfect but this isn't bad. Also the way I've set up on the flanks mean no player can be frenzied out for a crowd surf, this is important too. Another thing is that early on my blitzers are my key players. So I protect one of them to make sure I have a reliable blitzer standing up. The Thrower is also quite well protected. Early on I like to set my blitzers up centrally so they cover most of the pitch. Once I have more Block and Wrestle sprinkled I mover them to the flanks. Against a slower team I could move all the players one square closer to the middle and close off that gap.
However once I have two Blodging Side Steppers, probably the blitzers at level 3, I could change it to this.
xxxx-xxLLLxx-xxxx
xxxx-xxxxxxx-xxxx
xBxx-xLxxxLx-xxBx
xxLx-TxxxxxL-xLxx
This means that anyone trying to blitz me will be risking not knocking over my player, and I can use side step and set them up for a surf next turn. Also having Side Stepping Linemen is a long term goal as having one or two on the LOS could be very frustrating for the opposition.
Once I have Kick and Catchers, I have a lot more speed, so against a slow team I could set up like this.
xxxx-LLLxxxx-xxxx
xxBx-xLxxLxx-Bxxx
xxxC-TxxxxCC-xxxx
Now this means if my slower bashier opponent wants to maximise his hits, he needs to stack his offence to one side. I can then kick deep to the opposite corner, and whether I get a blitz or not there's a decent chance I can cut his ball carrier off from his bashier players and stop a cage from forming. If he receives perfectly and manages to get the ball carrier safe, then I have the speed to get men in good position behind the ball instead and initiate a stalling defence. Against a fast team this formation would be practically offering them a TD.
But bear in mind they're all options and it's also a matter of what suits your playstyle. I'm not so good on bashy formations, but tend to use something similar to the first example.