Uploading a video is a two-step process—on the next page, you'll be able to choose your video file and set the privacy settings. Generally, uploading will take 1-5 minutes for every 1MB with a high-speed Internet connection. You'll see an "Video Upload Successful" page when it's done, linking to other things you can do with the video while it's being converted, which will take a few minutes.
Videos are limited to 100MB in file size for all users, and 10 minutes in length unless you have been approved for a Director account. For more details about uploading videos, go to the Help Center.