You can use this generator to create the entire form for your email form including all fields, or skip the 'form items' section and just fill out the 'submit properties' to retrieve the code used for emailing forms and incorporate it into a ready-made form.
If you are doing it this way, use the first piece of code in place of the <form> tag already in your form, and the <input> line in place of the <input> button already in your form.
Form item instructions (if required):
select type of field
choose the value of the field, or what gets displayed within the field
choose a name for each field. This doesn't get displayed, it's an 'identifier'
choose lengths etc of fields as applicable
click on 'add item', then go back to the start and create another field if desired clicking on 'add item' for each one
when you have all of the fields you want, continue down to the submit properties and fill in the necessary information
click generate, then copy and paste the code where you want it on your page