It's really simple to start out:
1) Devote 10 minutes of each day to meditation time. Early morning is best, as your mind is fresh and not as distracted.
2) Find a quiet/non-distracting place to sit in a comfortable position. Legs crossed on the floor or in a chair are fine. You want to keep your back straight to help keep from falling asleep.
3) Focus on the sensation of your breath, wherever it is strongest. Typically this is the tip of the nose, or in the nostril, but chest can work as well.
Your mind will become distracted with work, worries, thoughts of food, etc. When this happens, congratulate yourself on noticing that it happened, and bring your attention back to your breath.
That's it! It blows my mind how developing concentration can have such a profound impact on your life.
Here are some good resources for those interested: