Been watching this thread for a while and thought I'd finally put my 2 cents in.
I'm as 55 year old grandfather who could not agree with Oldspark more, not only are grandchildren the greatest, but they are the greatest reason to keep going.
I have Cycling Past 50 and it is an excellent book.
I ride an EZ Sport Ltd "Bent". I've been riding for the last year, however only seriously for the last 4 months. Due to the temps in AZ this time of the year I can only ride early on weekend mornings (have to work on the other days). I will be adding more rides as we get closer to the end of September and the temps start dropping.
Four months ago I started by going around the corner twice (hurt myself last year and had not been on the bike since November 03). Last Sunday I did my longest ride 30 miles (averaged 12.08 mph, not fast but steady).
Just signed up for my first Metric Century on November 7th, Ride for the Children.