First: Make sure you have good, useful content.
Second: Sign up for a couple of affiliate networks if you haven't already.
Commission Junction is a good one and clickbank is another.
On CJ, apply to programs that are travel-related (luggage, priceline, etc). Run those banners/ads and text links on your site on your site. Do the same with clickbank. Sign up to promote travel products (how to fly free, etc).
Put those ads on your site.
Third: Also sign up for adsense. Run adsense ads within and next to your good content, so that people will click.
Now, as long as you have a good amount of traffic, you should be good to go. If you don't make sure you check out my
services in the Webmaster forum. I'm offering 5,000 real visitors for $5.99.
Good luck,
traffic_guy