Team composition: The best approach is to get three full lines as soon as you can. It's good to have replacement players for the ones that are tired and/or injured.
Basically, you want goalies with high Slam primarily. Then centers with high Lose, preferably high Get, and as tough as you can find. Then wings with high Lose (Get isn't as important since they won't be trying to win faceoffs). Wings who can hit (high Pound, mid-range defense stat) are good to have, too. Toughness is a plus here, too. Finally, you want good defensemen who can hit (high Pound). Tough isn't necessarily as important, though defensemen tend to be tougher by default.
When your orcs get tired, rotate them to the 3rd line. 3rd line gets less play time than 1st or 2nd does. Try to play your orcs up until they get to the next season. Then you have a choice - try to balance play time (though you'll probably not win as much) or try to focus play time in a small group of orcs (which means if they get knocked out, it hurts more).
Don't forget about tolerance. Tolerance is probably the most overlooked aspect of the game. If your tolerance is 1 or 2, you can bet your orcs will die, since they will try to stay on the field even when they are close to death. Tolerance in the neighborhood of 12-18 is fairly safe, depending on the level of your league. The more experienced a defenseman is, the harder he can hit! It's been known to happen that a defenseman knocks out a center in one hit even when the center is in full Plate armor!
You could spend some money paying back your loan, but that will likely be paid for you quickly enough. It's designed so that you get it paid back before the end of the season. Until your loan is paid back, though, don't put any money into rollover. The interest rate on your loan is a huge 5% compounded weekly! Interest earned on rollover prepayments is only 2.5%.
If you are not winning, don't worry - there's always next season.

Don't buy training facilities in your first season. Save that for after the first rollover, at the earliest. After a while, it's nice to have some training facilities, so that you don't have to try to get the absolute best orcs out there. You can get okay orcs and train them where they are weak.
Anything else I need to cover? Let me know if you have any questions.
- Brett