If you decide to take lessons, try to schedule them so that there is some time between so that you can practice what you learn at the range or play a round of golf. Don't schedule lessons so far apart that you spend most of the next lesson reviewing what you forgot from the last lesson. The rapport between instructor and student is important. The student must feel that the instructor is competent, and is providing objective feedback as to the student's progress. Don't be discouraged if you're not hitting the ball like Greg Norman after a few lessons.
Nothing can substitute for practice.
To get comfortable with the golf swing you need to practice it at the driving range on days when you are not playing the game. You can usually tell the difference. People warming up tend to shoot quickly. People there to practice take more time between shots and usually purchase a large bucket of balls. When at the range, try to practice the things your instructor taught you.