I only started running this time last year. But once I started consistently running 5 days/week I would use the other 2 as strict rest days. As I've improved now I will add in strength and cross training and only 1 (or 0) actual rest days.
I generally run T, TH, Sat. TU and TH being "short runs" anywhere from 3-6 miles. Sat are always my long runs. Anywhere from 7 to 15 miles. I feel like I am always in training so I don't change it up too much.