Summarize:

Put your contact information on your About page as well as a separate Contact page of your portfolio Web site. Your About page or separate "Hire Me" page should identify you professionally, represent you as trustworthy, display your qualifications and show off your best work as described in the General Advice section. You can include a "Hire Me" button that either links to this information from another page or to an e-mail contact application. Linking to the Web sites of clients you've worked for or to your LinkedIn profile is valid; linking to your personal Web site or to your pictures on Facebook generally is not. Include keywords that people looking for your services are likely to use, such as the type of writing you specialize in and where you're located. If you write copy in Denver, use "Denver copywriter" or "Denver copywriter" as keywords.  Place keywords in your Web page title bars and in the page text in a natural, readable way. Overuse of keywords in text will turn clients off, and many search engines will now reject sites with overused keywords. If you have keywords that people are likely to misspell (e.g., "writter" for "writer"), you may want to include those misspellings as keywords - just not as keywords that are visible on the text of any of your Web pages.
Make it easy for clients to contact you. Make it clear you're looking for work. Avoid irrelevant hyperlinks. Be SEO friendly.