One important consideration is to take as much Fan Factor as possible (must take 1-9) as FF is a key factor in determining how much money your team makes after a game. The more money you make, the faster you can expand your team. Usually when making my team I try to get 9 FF if at all possible, also as many rerolls as I can get my hands on. Apothecary is pretty important, but I usually don't buy it off the bat, opting for an extra reroll if possible, since rerolls double in price after you start the league. I usually buy my Apothecary after my first game and just hope no one dies or gets seriously injured in the first game. You need to have at least 11 players (less in a Big Guy's team) and at most 16 (max 12 in a Big Guy's team).

Sample Teams:

Dwarf
# Position Cost Each Total
1 Troll Slayer 90k 90k
2 Blitzer 80k 160k
2 Runner 80k 160k
6 Long Beard 70k 420k
2 ReRoll 40k 80k
9 Fan Factor 10k 90k
Human
# Position Cost Each Total
2 Blitzer 80k 160k
2 Thrower 70k 140k
2 Catcher 70k 140k
6 Lineman 50k 300k
3 ReRoll 50k 150k
9 Fan Factor 10k 90k
  Treasury   20k
Necromantic
# Position Cost Each Total
1 Werewolf 120k 120k
1 Flesh Golem 120k 120k
2 Wight 90k 180k
0 Ghoul 70k 0k
7 Zombie 30k 210k
3 ReRoll 70k 210k
9 Fan Factor 10k 90k
1 Dark Elf Lineman (Ally) 70k 70k
Orc
# Position Cost Each Total
2 Blitzer 80k 160k
2 Black Orc Blocker 80k 160k
2 Thrower 70k 140k
6 Lineman 50k 300k
2 ReRoll 60k 120k
9 Fan Factor 10k 90k
Skaven
# Position Cost Each Total
1 Rat Ogre 130k 130k
1 Storm Vermin 90k 90k
1 Gutter Runner 90k 90k
1 Thrower 70k 70k
7 Lineman 50k 50k
3 ReRoll 60k 180k
9 Fan Factor 10k 90k
Wood Elf
# Position Cost Each Total
1 War Dancer 120k 120k
1 Catcher 90k 90k
0 Thrower 90k 0k
7 Lineman 70k 490k
3 ReRoll 50k 150k
9 Fan Factor 10k 90k
2 Halfling (Ally) 30k 60k