It's generally not good form to ask people to e-mail, as that requires the use of a separate application, and most people will generally avoid it (I always do). If you have a field allowing comments in the form, people will also write something in it if they so desire, however, more people will simply fill the form out with just the basics (as well, more people will give bogus e-mail addresses, true)...
A form is pretty easy to create, and there are lots of scripts available online (many free) that can be used to create a form, but it's important to know what type of script is needed. Is the site written in php? is it jsp? what's handling the scripts on the back-end?
it is possible to only use a front-end script (like javascript), but that will likely also use a separate application (i.e. the e-mail application), which is quite annoying... and the only reason for using that script would be validation.
so, generally you would have 2 parts for a form - the html syntax (which nowadays is often written together with the script), and the back-end script, which does the submission of info and transfer to wherever it is you want (i.e. file download page or something)...