My suggestion is to call a local news paper or two and explain to the receptionist what you are looking for. Often times business will do anything they can to help students looking for information. Perhaps, if you call a small news paper, you may even get to talk to the chief or staff photographers directly.
In addition to that and concerning their wages, a sensitive subject, you can go to US department of labor website and search.
There is a link to Bureau of Labor Statistics. From there, there is a link to "Occupational Outlook Handbook"
You can search of "photographer"
There is everything you asked for in there
Oh, what the heck... here's a direct link:
While this information may not be specific to journalism, little further work will get you there
Your assignment has more to do with just writing about the subject - that is, a skill to look for information yourself is part of your assignment. This will get you there if you spend an hour or two looking.