This is a fantasy. Whether you are an unpublished neophyte or an author who has hit the big league, marketing is the name of the game. And like any other game, there are rules.
Rule #1: You are not selling a product – you are selling yourself.
Regardless of the concerted efforts of the publishing industry to turn books into products, they are not. Books are ideas. They represent what is in the author's mind – nothing more. Even if a book turns into a fad, which is what every publisher hopes, it is still an idea. Your idea. Which means that what you write is inextricably bound to who you are, or, who everyone else will believe you are. (I know what you're thinking right now. You have no choice in this matter, so don't even go there.)
This is how you begin:
First: Define yourself. Who you are is not determined by who you actually are, but by what you write. For example, if you write children's books you are cheerful, accessible, and any mother would be happy to leave her only child with you for a week. Your photograph will show that person – a friendly smile (with teeth), wearing parental clothing, in pleasant colors. If you write horror-thrillers, you can go with a brooding photo, either in black and white or in very subdued hues, no smile – or if you must, a Mona Lisa impersonation. Avoid portrait studios. Your picture is worth a thousand careers, so make sure it doesn't look like the one in your high school yearbook.
Second: Project yourself. Your website (and you must have one) should reflect your image. Of course, your writing will be showcased, but the site's mood will be determined by your writer persona. Same for the blog (and you must have one). Your picture will be on the first page of your website along with a brief above-the-fold bio. A different, smaller portrait of you must be at the top of every other page on your website. Anyone who views your website must feel as if she or he is getting to know you. Your blog should have a theme in keeping with what you write. (That means you cannot blog about your cat unless you write books about cats.) You can blog about writing, of course, but a lot of people do that, so unless you are famous, competition will be fierce. And remember: You are a writer - even when you are blogging. So give it your best.
Third: Establish yourself. After you have set up your website and blog (and you don't need to publish anything first), join online groups appropriate to your writing themes, get on forums, and make comments on other blogs. Use the name you write with – for example, if your author name is your full first and last name, that will be your “handle.” Be proud! Let people see your name, and your face. And don't write anything that you would not want to be read, out loud, in court, by a judge.
Fourth: Share yourself. After you have spread your name around, it is time to spread your website and blog. Join Linkedin, and post your website and blog on the appropriate discussions. If there isn't a discussion about sharing blogs or websites, then start one. Even as I type this entry, there are several ongoing discussions on Linkedin that encourage writers to share and “like” one another's websites. Join every group you can think of, alumni associations, Writer's Digest, Librarything, Goodreads, and post a profile with as much detail as you can muster. Needless to say, Facebook, Twitter and any other form of social media that has been invented in the last five minutes are valuable tools for building a following.
Now you can go ahead and publish. (More on how to accomplish that task to come.)
Good website: http://misaramirez.com/for-writers/marketing-and-promotion-part-one/
One author's feedback after five months of self-promotion: http://www.theloneliestplanet.com/2012/08/book-marketing-my-five-month-progress.html