Try it. If you can't figure it out, read further on this page.
Browsing and downloading: From the home page, there are two links for browsing: one for sorting files by submission date, and one for sorting by author's last name. When sorting by submission date, the most recent submissions are at the top of the list. If you see a paper you're interested in, click on the title, and you'll see a directory containing the uploaded file. If your browser is suitably configured, it may be able to display the file as soon as you click on it; otherwise, you'll have to download it and print it or display it on your computer.
Searching: Search is case-INsensitive, and search strings can match parts of words. Currently, basic searches match anything in the author, title, or keyword fields. For example, searching for "kennedy" finds at least all papers by Kennedy. Searching the archive with Google is a normal Google search with results limited to results contained in the archive, with all of the power and limitations of a Google search. For instance, you can search for words in the text or in the references of papers; on the other hand, if you're looking for papers about, say, determiners, you're better off using the basic search that only looks at authors, titles and keywords.
Uploading: go to the home page and click on "submit". You'll see a form that asks for author, title, file to upload, and filename to use on the archive. The author field should be filled in alphabetical order, i.e., "Barwise, Jon and Robin Cooper". The file to upload should be a path on your computer; most browsers will provide a button labelled "browse" that you can click to get a click-to-choose interface to the files on your computer. You can name the file that will appear on the archive whatever you want, though it would be wise to give the file a name that reflects its format: .pdf for PDF files, .doc for Word files, etc. When you've filled out the form, click on the button labelled "I certify that uploading this file does not infringe copyright". In a moment, you will be given an eight-character password. When recording the password, be sure and distinguish between 1's and l's and between 0's and O's. You will need the password if you ever want to delete the file using the web interface.
Deleting: From the home page, click on "Modify", type in the password you were given when you uploaded the file, and click on the button labelled "delete". The archive will respond with a description of the deleted file. You can check to make sure it has been deleted by reloading the list of papers (see "browsing" above). If you lose the password, you'll have to contact the archivers by writing email to if you want to modify or delete the file.
Tips: The file you upload can contain any kind of information. If you want to provide contact info, for instance, you can upload an html document providing addresses and links to your home web page. If you want to try this, be sure and give a filename with a .html extension when uploading.