Bill, I use Microsoft Office Power Point. That program was included in the software that came with the laptop, it is not the best but, you can insert arrows, etc., with it. I was using Photobucket to host my photos, etc. but now I just repost to FordBarn from FaceBook.
If you are running the windows system there is a handy built in program called "windows paint". That is the one I use if I want to crop, re-size, add captions or whatever other marks I might want on the photo.
I used it just today to crop this pic of the 52 Merc from a couple of days ago.