Yes there are patterns and a tute around.
Steve Good has a good starter pattern and vidio on it. That is what got me started cutting them. (Of course, I got totaly carried away with the whole idea and cut the "Plywood vase"!
)
Also Steve recomended (and I bought) a book by Carole Rothman called "Wooden Bowls From the Scroll Saw". Published by Fox Chapel. It was $20.00 US and worth every penny. You may however, find it in a library near you. I also think she has some vidios avaliable on line.
Hope that helps. They arent very hard to cut but getting some interesting wood glued up and all the sanding afterword is time consuming. You already have a headstart on the glue-up part!!
Rog