Teaching your church a new song doesn't have to be difficult. I've found the following method to be fairly effective:
1. If possible, play the song as people are coming into the service. You can use a recording or the worship team can play it live. (My preference would be to do it live as that way people will hear it the way it will actually be played during the worship time)
2. I would then use it at some point during the worship time (probably as the third or fourth song depending upon how many songs you do). I would introduce it simply by saying something like “this is a new song, it's called... We're going to play it through so you can hear how it goes."
3. I then play verse one, the chorus and the bridge if there is one. At this point (and if possible with the band still playing in the background) I say something like "that's all there is to it. We're going to play it a couple of times, feel free to join in when you are ready to".
4. I then lead the song as I would normally.
5. Sometimes I may play the song again at the very end of the service especially if it hadn't been played when people were coming in.
6. I then try to use the song at two out of three of the next services. I find that this helps to get it firmly fixed into people's minds.
7. If at any point during this process it becomes really obvious that the song is just not going to work with the band I have or the church I'm trying to use it in, then I stop using it. Sometimes a song that sounds great in a stadium with thousands of people just doesn't work in a church service with 50 or 60. Just because the song is powerful in one context doesn't mean it's right for every church and things that God uses powerfully in one place might not be appropriate in another.
Do you have a different method of teaching songs that works well? We'd love you to hear it.