A basic mailto: form is one option, but they actully work (or don't work) depending on the email client on the users machine.
Free hosted scripts (ad-supported) can be found all over the place, one I saw suggested was Response-o-matic
http://www.response-o-matic.com/
Alternatively:
Google it, a big list of possibilities
PS. Contact forms are NOT SPAMPROOF, I have a scummy little sod giving mine constant attention - would probably be worse, but the page it's on is only accessible through a form button, some further ways to resist, such as javascript generating the page, might be worthwhile.