I wouldn't get into the game of charging per word/hour. You don't want to commoditize yourself. I suggest looking into value-based fees. Here's a good place to start. http://www.freshbooks.com/blog/2013/06/12/breakingthetimebarrier/
Are you talking about travel writing, writing for websites or writing for magazines? It really varies. For magazines, sometimes there are directories in professional groups (such as ASJA or Freelance Success), or paid sites like MediaBistro or Writer's Market (which is also a book). There's even a tumblr called Who Pays Writers? (http://whopays.tumblr.com/) Writer's Market also has a chart of going rates for various projects, though I think what they say for copywriting is a little low.
If you're working individually with a site, I wouldn't go any lower than $1/word or $100/hour. In general, it's a good idea to keep track of your hours so you can begin to calculate pay per hour, though. A magazine that pays 50 cents a word but is easy to work with may have a higher hourly rate than a site which pays $1.50/word but requests a lot of interviews and research and/or multiple rewrites/revisions.
I'm not a travel writer, but found this for you. Great tips!
It's much better to charge per project or to offer a series for a fee. My experience with many years in travel writing has taught that a few good pieces can lead to an annual contract, to an ongoing blog or to a book. I'll be glad to discuss details of my recent mobile travel apps and books.
I wouldn't focus on charging per word either, though this can be helpful once someone gets more specific with you about what they're looking for.
When you're giving a price, think about 1. how much research the piece requires 2. how much time it will take you to do this research 3. how much insight you'll need to have about the site's "personal" brand 4. how specific and original the work will be 5. how much experience you have writing pieces like this. 6. how many revisions you are willing to do.
1,000 words off the cuff is a lot different than 1,000 words that have been well-researched, edited, and revised.
My feeling is that you're asking how much you should charge for travel writing in general. For a 500 word travel blog post that required "light research", I would charge at least $100.
Rates are very low in the travel space, especially online. You can expect to be paid per article not per word. You're looking at probably a couple hundred bucks for a 1000 word article, though that's at the higher end. Even CNN only pays a few hundred for an online article of about 800 words. Long time freelance established writers get about $1.00 a word.
Don't forget as you're doing your travel writing, you should be able to get certain things comped for you, like a hotel, special event or performance, or even a meal. While this doesn't necessarily pay you by the magazine, this is a type of income that can make the article much more rewarding.
I was a travel writer for the state of Indiana for a few years, and would often get to travel to different parts of the state for an overnight trip. I only ever made $25 or so from the article (state government doesn't pay much), but the value of that "vacation" was often worth a few hundred dollars.
Still, as the others have pointed out, $1 per word is a great rate, and you should take it when you get it. Otherwise, $150 - $200 for a 750 word article is not out of the question.