I am starting my first quilt..a disappearing nine patch and wondered which thread was recommended for quilting and where it could be purchased. This will be machne quilted not done by hand. Thanks

There are tons of threads out there for machine quilting. Coats & Clark makes an inexpensive good machine quilting thread, or you can spend more money on others such as Gutterman or Superior. It's a matter of what you like and what your machine likes.

Any good quality regular weight sewing thread will work for machine quilting. I use both polyester threads and cotton. I would caution against the really cheap stuff because it can be weak in spots and really slubby. If you do wind up with a bad spool of thread, don't hesitate to take it back to the store.
Although this is really personal preference, I suggest that if you want to use a lighter weight thread for the quilting to go with a polyester.