Picture problems

I have been trying to attach a picture of my fish. I am getting told that my pic is to large. My pics go from my digital right to my hard drive, through the software for my camera. How do I change the size. I wanted to put the pics up for to reasons. I wanted to show my babies, and I have a Cichlid that I can't seem to identify and wanted to see if someone here can.
I know its just a tad off topic but...

thank you

thank you OrionGirl. I did finally mamage to figure out how to fix the size in my imaging program.