Am I going about the Publishing thing backwards?

That really depends on what type of book you are putting together. Why do you need a photographer? Is this a coffee table type of non-fiction book? If you are looking for someone to do the cover of your book, don't bother. The publisher will look after that. If you are writing a children's book and you are looking for some pictures or illustrations, don't bother unless you are doing it yourself. Publishers would rather use their own people for this. Now, if you are writing a cookbook and want accompanying photos, or a travel book, or reference book (let's say information on gemstones) then I can see where you are coming from. But if it is any of the above stories I mentioned, you don't need to provide the pictures.

There are several ways to go about getting published. You can mail the entire manuscript in to a publisher, and it will go into the "slush pile" where someone far down on the publishing chain will read it in a few months. Very few books make it into print from this. Better would be trying to find an agent who is interested in taking this project on. An agent usually has the ear of several editors, and will try to sell the project for you (taking a cut for themselves of course). You can also try and approach an editor directly but these are busy people who tend to work through agents, who weed through a lot of manuscripts for them. I also knew someone who had a complete project who was able to get published by taking their book around to publishers at the annual book convention, a very unorthodox method. Then there is always self-publishing...not a road I would go down, but a lot of people are satisfied with this option. Good luck with your book.

You should send the work to the publishing company. They'll find a photographer compatible with the work. In other words, don't worry about an illustrator.