The user and pass would by the email account username and password that you set up in cPanel's mail settings (you can have up to 5 addresses in free hosting I believe). I'm not sure what the server is though because I haven't looked that up yet.
In cPanel under E-mail accounts, all of the information you need to set up your client can be found there. If need be, you can download a file that can configure your client for you if you're using Microsoft Outlook or Windows Mail/Outlook Express.