Ideally, you want a platform that will appeal to the prospective readers of your book, or at least your genre. As I type this it sounds remarkably stupid, so what do I really mean? I'm afraid you will have to write articles that touch or run tangent to the primary subject matter of your book. You'll want a 360 degree compass of topics on display, in your case just as you have listed: pure psychology, popular self-help, personal memoir. But also: popular sociology, the subculture of your psychological interest (I think that's the "sweet spot"), age and psychology, how you see the world versus how the world sees you, and so on.
This can be done as a BLOG or on FaceBook. But vitally, in tandem you must open a Twitter account where you can gain followers faster than on FaceBook I believe. You tease them with a 280 character blurb, and then direct them to the BLOG or FaceBook. It's not easy. Although Twitter may be faster, it will never seem fast enough. (Hint: To get followers, you must follow first. You can "beg" for followbacks, but some Twitter users find that distasteful.)
That's all I got, aside from hiring a fly-by banner with the title of your book over whichever annual nonfiction gathering has the most attendees. Good luck!