Lots of aspects to marketing, from social networking to your own website, traditional advertising, and drumming up interviews. I still haven’t figured out the magic formula, although weekly blogging and participation in book- and publishing-related groups or fans of your subject area of writing in the social networks seem to enhance success by helping you build an audience over the long term (read that long-term thing again).
Social Media
I favor LinkedIn for business networking (it’s a lot less retro than it used to be). Facebook basically keeps you invisible unless you already have a big following (even if you buy ads). I’ve heard some good things about being on Goodreads over the long-term as well. Amazon as a marketing network is a mixed bag; like FB it’s got lots of theoretical reach, but it doesn’t give extra visibility to small-scale self-publishers. You really have to take charge of building your own fan base by participating in subject groups, promoting other authors in your genre on social media, etc. This is a find-and-grow-your-tribe kind of thing.
BookBaby has a nice article on book launches if you are interested in further details for planning your initial campaign. You’ll see that there’s a lot involved, and you may want to recruit a little team to help out.
Website
Also, it’s quite helpful to have your own web-based territory, a website of your own. There are all sorts of options for setting up a website, some more intuitive than others. If you really want to go it alone on this one, I recommend Weebly or Squarespace. WordPress is ubiquitous, and I like its customization capabilities, but it can be a bit of a learning curve to get something simple up and running. I can help you set up a simple WordPress, site, or help you tweak a Wix, Weebly, or Squarespace site if you are interested.
Agents
Finding an agent is a form of pre-publication marketing on your part. The agent will act as an outside acquisitions editor, ready to sell your book idea to a publisher they are connected with if they think you have potential for a traditional publishing contract.
There’s nothing wrong with shopping around for a good literary agent (particularly for fiction) or presenting a book proposal to publishers who accept proposals and/or manuscripts. The agent may be your best bet to get recognized by a traditional publisher, but first you have to get recognized by the agent (who usually gets paid a commission on your royalties after successfully selling your book to the publisher). Reedsy, an author services organization, has a nice article on query letters for agents.
Book Proposals
Another option is, of course, to send a proposal or manuscript to a publishing company. Large companies will likely only take proposals, or only proposals from agents. It is very rare for large publishers to take full manuscript submissions. Normally, authors submit a book proposal based on questions and categories set by the publisher, but there are a lot of common elements.
Here’s a download of the types of information to put in a proposal for a nonfiction book.
My Recommendations
I have a couple of book publishing marketing experts to recommend. Both can help you with the process of giving your book the best launch, along with offering lots of other links to services for authors:
Dan Blank at WeGrowMedia
Lil Barcaski at Ghostwriters Network Publishing