Step 1: If you are friends with Oprah, you don't really have to go any further.
Step 2: Make sure some sort of horribleness has befallen your life. All of the greatest authors have had any combination of the following: undiagnosed clinical depression, substance abuse, being poor and hungry, having abusive parents (or--even better-- aunts and uncles who unwillingly took you as their ward), or communist sympathies. The more of these combinations you can scrape together, the better writer you will be. If you haven't had the fortune to be so misfortunate, try paying your water bill late three months in a row and see what happens. I bet the muse just starts a-talkin' then!
Step 3: Figure out what sort of book you want to write. There are centuries of genres you can choose from, but you are better off randomly selecting something from the current best seller list and copy it. You can certainly write the Great American Novel with grand themes about struggle, pain, and social justice, but if you want anyone to even give your book a second glance it, let alone buy it, had better be about surly teen vampires, sexually frustrated housewives, or juvenile wizards. Slip in some feminist dialectic if you heart wants to, right after you introduce the talking rat in the leather swing.
Step 4: You should also figure out what sort of plot you want. There are some very common themes, such as unrequited love or struggle with an internal villain. Pretty much every novel in existence is a variation on this theme. You get bonus points if you can work in some historically repressed demographic as well, so get ready for some conflict between young quaisgendered Bohemians and environmentally conscious Hispanasian women down on the kibbutz.
Step 5: You must determine whether you want your protagonist to be a hero or an anti-hero in your novel. Most traditional novels had fascinating heroes--Captain Ahab, Mr. Darcy, Humbert Humbert--but this is no longer the particularly trendy thing to do. Making your flawed character an anti-hero will not only help you write a modern novel, but you can project all the horrible things people have ever done to you--from the college admissions clerk all the way down to that barista who gave you a scornful look when you asked if she wanted to hang out at some dull book club like it was some sort of date where they, regrettably, do not serve alcohol--and wrap it up in your horrible, horrible character.
Step 6: Get started on actually writing your book! Different authors suggest different methods to write your novel. Some suggest the brute force technique; simply write anything and everything. Since it can all be edited out later, surely something worthy will spill out on the page. Others will advise to sketch out an outline and stick to it to keep you disciplined. Most likely you will use a combination of several methods, along with a healthy dose of inspiration, dedication, and blatant plagiarism.
Step 7: For the love of all that is holy, use a laptop. Don't try and write your novel on actual paper. Some pretentious charlatans will try and tell you this is a more "pure" form of writing, but it's all baloney. Not only will you never finish your novel, you're going to look like a complete prick the entire time you hack away at your aimless pursuit. There are many ways in which you can manifest your crippling sense of self-loathing, but getting a spiral-bound notebook and a pack of cheap Bics isn't the answer.
Step 8: Don't ever, ever use the word "baloney" even if it's legitimate. It's crass and uncalled for.
Step 9: If you haven't already taken up an addiction (see step #2), you should start. Writers are a particularly addictive lot, but they are also famously poor and so their addictions are usually of the--shall we say--easily attainable variety. Caffeine is usually a good start, since you can run through a pocket change's worth of pots over the course of a season with your gastric health busted, but not your wallet. Nicotine isn't far behind, especially if you don't have any self-worth and are more than happy to roll your own cigarettes. However, you must use these addictions to fuel your work; do not let them become the reason you get up in the morning. Also, make sure your addiction is stimulative in nature; too many writers get addicted to things such as Bad Girls Club marathons, claim they are for "inspiration," and just end up ordering all of the seasons on DVD from Amazon while your unfinished work sits embarrassingly unfinished next to the remote.
Step 10: Stay true to your plot. It will be tempting to stray from your original ideas as the words become harder and harder to write, but if the book is worth writing the words will find a way. Granted, there's a pretty good chance that your book is not worth writing, which is why there are so many obnoxious books about horny vampires flying off the shelves.
Step 11: Don't be afraid to let a good copy editor look over your work when you are finished. Every single author believes that each individual word they write is sacrosanct, and are unpleasantly inclined to let someone else tear them apart.
Baloney Nonsense. You need someone to
shamelessly rip your beautiful words to shreds and force you to reconstruct
them in a more palatable manner. If you wanted perfection, you should have
taken up engineering. Which--let us be fair--you probably should have done
anyway. Although I doubt STEM was really your sort of thing anyway, what with
you thinking you could write a novel.
Step 12: Even if you do not get your novel published--and let's face it, you probably won't unless you've followed Step 1--you should still feel glad about this sense of accomplishment. You have written a novel, which millions of people would love to do yet very few have actually done so. Sadly, a million more can't write a novel and yet have done so, which is why there isn't a chance in hell of you getting published. I suggest trying zombies next time.