Hi,
Welcome to the world of Warmaster and 10mm, (be careful once you've played you may not want to play another system or scale

).
There's a good choice of dark age armies, some list are in the main rule book others are in the Warmaster Armies book.Which to take? that choice is yours if you like Inf armies then it would be Saxons/Vikings etc or Normans for Cav type armies. My personal choice of Dark Age armies for a good game is Normans vs Arab Conquest (aka Battle for Sicily.)
Which manufacturer to use? theres some good 10mm about. One thing to remember is at the moment each manufacturers 10mm is a different size so if buying an army get all units from the same manufacturer in that army, don't mix and match.You'll see what I mean if you put an Kallistra fig next to a Pendraken (looks a bit like Land of the Giants

)
My personal favorite is Magister Militum a good cast, nice size, good to paint and a great service.That said ive got armies from most of the manufacturers and to be fair they are all good.
If you click on the link to my Blog you will find links to all the 10mm manufacturers
http://grandscalewargaming.blogspot.com/Hope this helps
Jason
