Start by finding a book that you like. It can be anything, from Harry Potter to a sci-fi book. You will probably be drawn to one genre more than another. Some people really like romance while others love mysteries. Find one that's best for you.
Judge the book by its cover, for a second. If it's called "Thirty Different Tragic Airplane Crashes" and you are deathly afraid of flying, then obviously you should not read this book. However, do not judge a book JUST by its cover. Read the summary (if it has one, it will be on the back or inside the dust jacket) and if it seems intriguing, open the book and read the first page. If you like it, keep going. If not, find another book.
Do not read while you're making dinner or trying to clean the pool. Read where you know you will not be interrupted. Turn off the radio and TV, put your phone on vibrate and just read.
Go somewhere that enhances your reading experience. If you're reading a light and airy novel about springtime, sit in a brightly lit room that's pleasantly warm. If you're reading a thriller, sit somewhere that might produce a loud noise every once in a while (maybe outside of the garage while someone's working in it). While some people may find that when they read they are completely oblivious to everything around them, others find that if they immerse themselves in the same settings as the book's characters, they can get more involved with the story. Wherever you read, make sure there's enough light.
Highlight (or underline in pencil) any word you don't understand. Later, look it up. This will greatly enhance your vocabulary.