Getting the sheet music together for your music ministry and not breaking the law can be a bit of a challenge. Personally I think that a lot of the songs can be written down straight from the album almost if the music provided is limited to lyrics and chords.
Many use the CCLI site, for New Zealand that is http://www.ccli.co.nz/.
Other sources you may want to consider are:
You may, especially when you are a guitar player, E-chords which has a lot of free download materials available.You will need to register for the site though. For the individual musician try “free sheet music” plus the name of the song or when you are a guitar player the same but for instance use the key search “free guitar tabs” and the name of the song.
My best advice however is to just train yourself in getting the chords together yourself. Most of the time the songs are not that incredibly complex and the more you do the quicker you get at it.