Hi gheventer,
I was reading a lot about querying NF - (realized that since my MS was basically a memoir, the rules are closer to fiction -- but) sounds like with your type of deal you should start querying now. (They may want to have input on your photo-illustrations anyway.)
Seems like what they're mostly gonna want is: Who the heck are you -- and what qualifies you to write this book?
Is anyone (besides you) aware of your qualifications? (blog or website)
Short description of MS -- including who you think would want to read it
Outline of the proposed MS (by chapter)
Sample chapters --(to see if you can actually write)
Use the first three to formulate your query -- get 'em out there -- have the last two ready to go (in case somebody asks) -- and in the mean time, you can get some photos ready to submit in case they want to see them
Hope I helped
Regards,
-oldbag