I have a County Comm.
Some binders will fit, and some won't. I have a nice binder from Staples that has rubber edges on the cover, and it will not fit well enough to zip the bag. (BTW.. their house brand binders are very well built... see link:
http://www.staples.com/sbd/cre/products/090614/merch023952/index.html)
But standard 8 1/2 x 11 is no problem. You'll find something that will fit fine.
As for the netbook, I doubt that you will be able to fit anything that large in the secret compartment.
Now.. is it a good bag? Yes, for the money it is a steal. But it is not as durable as a Maxpedition, so expect it to wear. Mine was EDCed for about a year, and it has a few wear spots on the outer tube shaped pocket. They are not holes, not yet.. but they will be.
So if you are rough on a bag, you might want to spend more for something tougher.
That said, I love the County Comm BOB, and would buy another in a heartbeat. It is a lot of bag for the money.