Bankroll is the amount of money you have designated for gambling. Keeping your bankroll separate from your personal finances is a good way to avoid gambling problems. Bet Max is a button on the slot machine which gives you the option to play the maximum amount of coins the machine allows. This tends to speed up play. If you have been playing one and the same slot machine for some period of time, you will be rewarded with casino comps. With these comps you can get free meals or even cash in some casinos. House Edge is an amount the casinos is sure to receive over a long period of time. Payback is percentage amount of each bet dollar, that is paid back. If you play the slot machine with 86% payback it means that it pays back 86% and 14% is the house edge. Remember that these amounts are taken over a long period of time.

Know what you are playing.
Always make sure that you insert the correct amount of coins into a machine. Cash your credits and only the leave the machine.
Slots shouldn't be a stress for you, just enjoy. Use money management. Increase your bets when you are winning, and decrease your bets when you are losing.