Not quite sure what you want to do, but the simplest way to let people e-mail you is to add a link pointing to the e-mail address e.g. <a href="mailto:[email protected]">Questions</a>. When the user clicks on a link then a 'Create e-mail' window will be launched by the e-mail client (assuming they use one), and they can fill it in and send it.
The other option involves using a form and some sort of script to send the e-mail, removing the need for the user to have an e-mail client. Plenty of scripts freely available to do this, just depends what you can use.