I am extending my driveway to what is currently part of my yard. I plan to use gravel only. What can I do to prevent the grass from growing up through the gravel. I thought about landscaping paper. Will that work? Thanks.

Yes, the landscaping barrier works wonders. For added treatment, though, you can first apply a ground contaminator like one of these.

This should stop any weeds for at least a couple or more years.

Eventually weeds will probably break through, but if you saturate the area with a contaminant every 2-3 years you should be nearly weed free.

Total vegetation killers works great! I had gravel driveway and I know what a pain in the but it can be fighting those weeds and grass. It's much easier and less expensive just to use the total vegetation killer.