From Bayesian Behavior Lab
To upload a file to the wiki, follow these steps:
If you have problems, make sure the title doesn't have weird characters (& or $ or ' ' for instance). Also, make sure you include the extension (.pdf or .docx) in the link.
From experience, files larger than 20 MB may not succeed. Try splitting large files.
If the file extension is not explicitly allowed in the DefaultSettings file on the server, the file won't be loaded. If your file extension does not show up on the list of "preferred" extensions, it won't be allowed. The "prohibited" extension list will turn red, but even if you're file is not there, it won't be allowed. Contact Ben Walker if you want to upload another kind of file.
Linking to files
Unless you have a good reason to do something different, it's best to use the keyword Media for documents (.pdf or .docx or .ppt for example) and File for images (.jpg or .png or .gif for example). Some instructions on how to use these keywords can be found here. Some simpler instructions about how to link in general can be found here.