Yoga, yes, definitely will help with flexibility. But honestly, I find that I don't get enough of the stretches I want in a 1-hr class (*maybe* in the 1.5 hour classes...). And most classes, even with the same instructor, will focus on different areas in every class.
And - especially the flow classes - often I feel like I am throwing myself into poses when I am still so stiff. I neeeeeed more stretching!
So - I would recommend (to myself also!!) learning the yoga stretch moves and doing them at home, but holding them much longer than is done in an average class. I came across a book called "Cool Yoga Tricks" by Miriam Austin that has lots and lots of variations of the most common yoga poses. It really helps you get into them with proper form as you develop flexibility.
Check out the illustrated poses at
Yoga Journal - you can search by
anatomical focus, too - for example, hips, lower back, upper back. Have fun!