Although it's possible to upload other kinds of files, most people use this feature to upload images. See our image policy for how, when, and why to upload images to Wikitravel.
First, consider if the file should be used only on the English version of Wikitravel, or if you want to let the Wikitravel guides in other languages access the file as well.
On the appropriate upload page:
Here are some good summaries:
NOTE: Under no circumstances should you upload a file when you don't know exactly who the author is, and you don't have explicit permission to release it under our license. We cannot take files uploaded under the idea of "fair use", because not everything we do is covered by that. We can't take images from Wikipedia either, because their license doesn't allow switching files to CC-BY-SA. Don't find pictures on the Web and upload them here and expect nobody to notice, either. We also can't take photos with recognizable people in the picture, unless you have an official model release from them. It's important that Wikitravel stay free for everyone to use, and free of copyright violations.
If all of this is OK, press the Upload file button. As long as the file isn't too large, and there isn't a name conflict, it should go ahead and transfer from your computer to the server, and the file will be immediately ready for you (and anyone else) to use!