Thank you for your service to the church! Some information and links that you might find helpful are below.
The Association is a terrific resource for Presbyterian church musicians, both paid and volunteer. The Association offers three levels of certification for church musicians. You can find out much more about the organization on their web site.
Call to Worship is published quarterly and available by subscription. Members of the Presbyterian Association of Musicians receive a subscription as part of membership. Samples are available at the link above.
Glory to God, the Presbyterian hymnal
You can purchase copies of the hymnal here in the PC(USA) Store.
Find information on the Presbyterian worship service elements at the link above.