TrekTheKaty,
Thanks for the tips.
I am trying to find a group ride, but most of the cycling clubs seem to be older men in my area. There is a woman's ride from my bike shop, so i am going to look into that. I do most of my riding on a bike trail, so I suppose I need to get much more comfortable with riding with cars, etc.

I liked your plan because it is sort of what I worked out on my own, by having one long ride per week, and adding 5 miles every week, or sometimes sticking with one mileage for 2 weeks..something like this:
Week 1: 20
Week 2: 25
Week 3: 25
Week 4: 30
Week 5: 35
Week 6: 35
Week 7:40
Week 8: 40
Week 9: 45
Week 10: 50
Week 11: 50
Week 12: 55...etc.
But you definitely think I should take off one week of rest, or just one long ride rest at times?

Thank you again!