It's kind of a broad subject, and you're very vague, so it's difficult to give good help. But here's some bullet points for you to work with:
Doing things without user intervention
Look into using a service, the forum is full of info about this.
Upload files to a website
Your best options are probably to either use an api on the server that accepts your uploads, or set up a public ftp server. I'm fairly certain that the forum contains info on uploading files using ftp, and it's fairly simple doing the same using a simple api on the server. Either way you need to have a lot of cooperation of the server.
I can't really give better help than this without a detailed description on what it is that you're trying to accomplish.