Many of the church volunteer scheduling services also have this built in. For example, Planning Center has an entire module for planning out services; where you can put media files there for your projection slides, music, practice files, sheet music, etc.

We use this at our church.

I'm not saying the DIY approach suggested by others is wrong using google docs, but there's lots of folks and companies that have thought long and hard about this and put great tools in place to make your life easier in planning services.

http://www.planningcenteronline.com/

-Scott