I Am Middle Aged and I Don't Know Where to Start

DO NOT GO OUT AND BUY P90X, INSANITY, OR OTHER HARD CORE WORKOUT!!!!

Something is better than nothing.  And too many people quit doing anything because they are pushed too hard.  I am glad you are honest here.  Keep in mind 5 days a week is the magic number,  Preferably 6.  That doesn't mean it has to be intense, just consistent.  In other words, the most important thing to remember is that you actually do whatever activity you choose daily. 

1)  Exercise 5-6 days a week minimum.
2)  Each workout should be at least 10-15 minutes.  (eventually you want to be doing 30 minutes)
3)  It does not have to be high intensity, just consistent.  (Make sure your heart rate is up)

Options: 
1)  Brisk walking each day.
2)  Water aerobics at the YMCA
3)  Fitnessblender.com   (any of the beginner-intermediate level workouts,  rotate through yoga, core, cardio, etc)