Choose the form of your book. Two good methods are eBooks and Print on Demand (POD). You can do either of these with relatively nominal costs involved. Typically, for less than $1,000, you can get your book ready for readers to purchase.
Build a website if you don't already have one. If your site is all about kitchen gadgets, but you've written your first novel, consider getting a separate author site. You can buy the domain name of either your book's title or your personal name or pseudonym. Hire a pro to help you if you don't know how to create a website, or use templates you can download from site hosts.
Make a business card and print out at least 100 for starters. Batches of 500 or 1000 may be more cost effective, but have some on hand. Put the website on the card. Do this also for postcards you can create using the book's cover. These are great to distribute at various shops, stores, meetups, readings and so forth.
Set up a video camera on a tripod or ask a filmmaker friend to help you create a book trailer. This is a short two or three minute -- ad-like video that does one of several things. For a basic trailer, record yourself reading a part of your book after making simple introductions. Another option is to be on camera talking about and promoting your book. A third route is to take concepts from the book and compose a slide show of video using voice over audio.
Write a press release and get it out to every online press release site you can find, as well as to your local newspaper. Distribute several books to reviewers and post their reviews to your website. Do interviews with local radio and TV shows, as well as online radio programs for your subject matter.
Start talking to people -- this means everyone you know, such as friends and family; then broaden your scope to include bookstore owners, libraries, reading groups, writer groups and so forth. Hand out business cards, post cards and share your enthusiasm for your book. Show a print copy so people can see your fabulous cover design.
Make a PDF version of your book and set up a simple online payment method. Upload it to your website and set up the coordinating information so people can go to your site, click a button, pay for the book and download it.
Set up accounts on all the online book distribution sites, including those for the various electronic readers. Upload your book to these sites and ask family, friends and other writers to write honest reviews to help kick things off. Soon, you'll know what the general public thinks.
Email everyone you know to share what you are doing. Share your site links, online book distribution pages and review links on your social pages. Having an actual "author page" can work well to start creating a buzz around your book.
Contact local book stores and go in person with a hard copy of your book. Tell them you're a local author and ask for a time to do a reading in the store. You can also ask if they'll distribute the book. Consult with the proper management personnel and build working relationships.
Offer to attend book groups to do a reading from your own material. Take extra copies to sell. Make friends, shake hands, smile a lot -- from your authentic joy in having written your own book.
Keep a consistent level of effort moving forward daily on getting your book "out there." Don't take any "bad" reviews personally. Just keep moving. Share, share some more, and get people to the proper sites to purchase.