You can self-publish through venues such as Lulu.com or CreateSpace.com. Both venues offer publicity packages if you wish to buy into one. Otherwise, you will have to try to market it yourself through repeated tweets, facebook pitches, google ads, etc. You need something that will make people want to buy a print version of something you've already been posting online. Who is your target audience? Why should someone buy your book? Has it been reviewed by anyone? If so, can you include their comments on your cover and/or in your online campaign? If it has not been reviewed, you might want to send out free copies to people for review. Be prepared for honest feedback and make adjustments as needed/wanted before sending it out for publication. I have two books published on Lulu. I like that publishing doesn't cost me anything - the buyer pays.