Signing up for a race will bring instant motivation and help you find a running routine. It doesn't matter if the race is 1 mile, 5k, a marathon, or stair climb. It doesn't matter if it's one week out or six months out. As Mark Remy says, "a race - weeks or months away - is the proverbial carrot, dangled out there for you to pursue."
To solidify the commitment, sign up with a friend or group of friends. This way you will have not only a goal on the calendar but also a support group to keep you accountable for achieving it.
So how do you find races to sign up for? My favorite source is Running in the USA, a site that lets you find races by date, type, distance, and location. It even has a "Double Stater" gadget designed for marathon maniacs like me that shows you races on consecutive days in different states, sorted by miles between cities.
Marathon Guide, Strava, and Facebook are places you can also find reviews and commentary for races to help you narrow down all the choices. Did you know there are 12 marathons that take place every year in Nebraska and 120 in California? Massachusetts has 8 stair climbing races. Read reviews about the course, logistics, and fan support.
Look for a course that excites you, whether it's the surface, scenery, elevation, altitude, or even something fun like the number of live bands. Choose a well-organized race to avoid issues like taking the wrong turn, aid stations running out of water, or waiting extremely long for bag check or a bathroom! Races that offer free pics are always a plus.
Finally, you can stalk your friends' and your own racing at Athlinks, a LinkedIn of sorts for runners that has the most comprehensive database of race results across the globe. Signing up for a race will let you see the results of your training, experience the running community at its best, and enjoy post-race treats. Just be sure to avoid the post-race bagels. It's a runner's rule that they must be dry and taste like aspirin.