I wrote an article about creating mailto forms. You use the mailto:email_address in the form action attribute. Don't forget to set the encoding type to text/plain.
<form action="mailto:email_address" method="get" enctype="text/plain"> ... </form>
Another option is using a free Form to Email script. This will provide you with the results you need in a form that is usable. One that is easy to use is Freedback.
It is easy to use and it accepts any type of form information. Once you know the hidden fields it requires you just set up your form with those fields and you're set.
If you don't want to use them, there are lots of other forms available: