Don't forget to eat...
Hi Caroline,
I just went through the same journey you are embarking on. The biggest advice I can ad is that when you get up to around the 40 or 50 mile distance, you'll definitely want to eat during the ride. Take power bars or whatever you like, but it is a must over a certain distance. I was able to ride 58 miles after about 4 months of progressive improvements. And I was a total couch potato.