Personally, I would not fire all of your players over 19 years old. I think that is a terrible idea, to be honest.
I would start by getting rid of all the players under 3000 salary to free up some money for salaries. I know it's a lot of players, but they are not very good and won't help your team. I doubt they will sell, so you will probably just have to fire them.
Then, start buying some new players. You should probably start with players inbetween $5000 and $10000 salaries. These players should cost less than $100 000, so you don't want to spend too much moneyon them. When you are buying a player, make sure they are balanced in their skills. You don't want a player that can only take free throws, for example. Make sure they are good on offense and defense, or they simply aren't worth buying. There is some debate about the best players to buy and train, but that is up to you. Also, you shouldn't have two great SGs and no bigmen, or vice versa. You need good starters before you can start working on your bench.
You can also train young players to be your teams next star. I would train Delmer Hamlin since he is 18 years old, has decent potential, has a high salary, and is tall enough to be a bigman. You can train Casey Barbosa along side him so that you get more out of your training. When you are training, single position training is more efficient than training the whole team. For example, a player might pop twice as quick in inside shooting if you train it for just Centers instead of for the whole team.
Finally, once you have a solid roster, you can start fiddeling around with your arena. You can change ticket prices or build more seats to make the most money you can from it. Investing in your arena early in the game will prove to be worth it in better leagues.
Good luck!
Last edited by Egg-Man at 8/1/2011 6:14:54 PM