You have to keep yourself on edge for the Lord and be excited about your Christianity. Select the few that are really faithful and get radical about your love for God and call them higher. This will spark others into following. The greatest among you will be your servant. Walk like Jesus and the spirit will put many messages on your heart.
Notes are good to collect thoughts but use a outline instead of wordy notes.
You should be filling excited about your message because of your personal walk with God. You have something to impart to your fellow brothers and sisters. This is the holy spirit working in your life. If you are having trouble with what to deliver maybe your walk with God is superficial. If you want to be a powerful and effective leader do the will of God and the many will follow.