Suggestions For Number Of Words?

You mention you're new, so I'm not sure if you know this or not, but if you price at less than $2.99 you only get 35% royalty.  $2.99 and above gets 70%.  If you haven't already, you may want to factor that in.  Plus, if you have photos in the book making it a bigger than B/W file, you'll lose part of that royalty in DL fees.

My suggestion is to DL some competitor books that have done well and have great reviews and shoot for a similar length.  Good luck!!

If I was doing a travel book, I'd do a series, focusing on a different area in each book. I'd try to keep it around 50K.