Thanks everyone for your help and advice! I sent the guy an email saying I would do the map for somewhere in the range of $13 - $15 an hour and a signed copy of the book it was for. He already knows I'm a fan, so that (for me) makes it an even more exciting opportunity. He just emailed me this morning saying that that price range sounded good, and he would talk to me about it some more tomorrow.

One thing though, early on when I was 'slower' ( I was never slow), I guesstimated on what my time to create would be if I were faster, so in the beginning I made less per hour because I took longer to do the work, but I didn't charge that difference to the client. What I thought should take me 4 hour to do, might have taken me 8, but I only charged for 4 hours. Now I am almost right on in my quotes for time, as I have a good idea looking at any map, how many hours it takes me.
I'm certainly not very fast yet, but I don't think I'm half bad. My first map took me around 18 hrs on and off. However, I did take my time with that one because it was for my own book, and I'm really happy with the outcome. However, now that I've done it once, I think I can be faster the next time. I gave him a time estimate and calculated $ per hour x hours worked on. He thought it sounded about right, so I'm not going to change it yet. I really appreciate all the help. Thank you so much!