You see them everywhere….. our electric co-op has two going right now, one for the monthly newsletter they send out, and a second for their yearly calendar. Yes I plan on entering both. Others for wildlife in our state I have found by searching in the internet different wildlife agencies, there are also national wildlife contest , and contest sponsored by tourism groups in many cities.
My hubby just entered three photos in the Friends of the blue ridge parkway contest, he took second place ($75) last year and that got us started. I still have to upload my three.
Make sure you read the rules and understand what they are looking for. Most of the time they want prints but some you can inter on line but this means resizing the photos to fit there needs.
Also check the deadlines carefully. I have missed several by just a day or two because i got my dates wrong.
You just have to be careful with the rules and make sure that YOU retain the rights to the photo, and know exactly where they will be publishing it.
Also do not be tricked into paying a company to publish your photo in a book. There are many of these scams on the internet. I know a man who paid $200 because his photo was “chosen” to be published, he finally did receive a book of very low quality photos of which his was one of about 1000.