FormsWeb forms are very nice to have if you want something more sophisticated than a guestbook. Everyone wants feedback on their page, or surveys, or whatever. The difficulty is that while forms are built with HTML, they can't be processed with HTML. They consist of two parts: the form's HTML code and the processing software.
Form HTML CodeIf you want help writing the HTML for a form, read my separate page about Building Forms.
Form processing softwareThe processing software deals with form data it receives from anyone who submits an associated form. It exists on a web server, not on your computer. It can do anything with the form data, but it is often designed to e-mail the data to the form's creator. Or it may put the data in a file for later retrieval, or use it for a credit card transaction (at an online retailer, for example), or FAX it to the North Pole for that matter.
For a beginner, I don't recommend attempting to actually write form processing software. It is beyond the scope of this guide, it usually involves a lot of ugly logistics, and it's not necessary for simple e-mail forms. The easiest solution is to let someone else (like your web site provider) process forms for you. Web providers often include some method of form processing (usually e-mail forms) as a free service on any account.
If you want a relatively simple form, but your web provider doesn't offer form processing, you can use a site like Bravenet or Freedback.com to create a form. They will e-mail simple form results to you for free. It's nice, but you shouldn't count on it for any private information, since the form data must go through many hands before you get it.
If you know of any other form resources, I'd be glad to know! When it comes to free services, the biggest problem is finding a reliable web site.