?'s about sending photos to magazines

[rivy]

I want to send in some pictures of mine to "Working Ranch" a magazine. They will use the photo in the magazine then give the photographer credit. First, I want to try to publish & sell some of my photos in magazines. How do I go about the copyright legal stuff. I bought a book on photography copyright and it is really confusing. I already got a photo published in Texas Agriculture. I take a lot of rancher/ranch and rodeo shots. Does anyone have any suggestions on this subject. Thanks, ronda