Here is a clickable list of FREE Image Resource Sites.
These are truly, totally free. No attribution required, no copyright infringement, OK to use for Commercial purposes (and for churches that means you can sell a t-shirt with an image used and be legal). I've spent many hours reading the fine print so you don't have to.
There are thousands and thousands of images here and I recommend doing searches for what you need ahead of the time you need them. Just save in files under the categories you know you'll be working in (holidays, various ministries, etc.) and you'll have your own store of images when you are on a deadline to produce communications.
For a video course on how to make the most of your images AND for a video preview of each of the sites and how to download the images (which varies from site to site), go to our course Free Image Sources, Tips for Use, Tours of 21 Sites. This course is part of our Church Communicators Training School.
Though the course has lots more that will help you, I thought everyone would benefit from this list—enjoy!