http://webdesigntuts.com/web-design/how-to-design-the-perfect-form/

When your users have dedicated enough time on your website to be interested in your service or product, and want to learn more, there is no bigger turn-off than an inaccessible, unusable form. A form can be anything from a sign-up form, to an email opt-in form, to a contact form, and more. You want to make sure that these forms are convenient, easy to use, and of course, good looking, for any of these visitors that are interested in what you do.