If you’re going to use WordPress, then at least install the All in One SEO Pack. It’ll do alot of work for you and enhance each page specifically.
Another one, which I consider a must, is the Akismet plugin. If you’re after good usability, then you’d want to remove any CAPTCHA-field in your forms. Akismet will help you out with that. Only requirement is that you register an account at wordpress.com. You don’t have to use it after registration.