Private Pilot

Step 1: Be at least 17 years old by the time you take the checkride (all eligibility requirements to take the checkride can be found in FAR 61.103)
Step 2: Get a Medical Certificate (first-class if you can, but only a third-class is needed to be a Private Pilot. Almost always the same price, no more than $50 or find a different Aviation Medical Examiner!). 
Step 3: Find a Flight School (click the link for more details).
Step 4: Take the Written Exam before you begin flying. Use Sheppard Air for study. It is the easiest/most affordable way to get through the ground training.  You will need an endorsement by your instructor (supplied by the Flight School in step 3) to take the test. Other online ground schools that provide the endorsements (Sporty’s, Gleim, etc.) are overpriced and don’t prepare you nearly as well as Sheppard Air. 
Step 5: Start flying with the flight school. Understand the Minimum Requirements to take the checkride and hold yourself to those minimums. It can be done! Flying frequently is the best way to do it. The longer the time you have between flights the more you will forget. 
Step 6: Take checkride with a Designated Pilot Examiner (almost always provided by the flight school, but can find your own if needed).