The best thing that I ever did was put down a geotextile mat before I put rock on my 600' driveway. Something like this.
Geotextile Mat I looked at the geotextile mats, but they would be a little pricey for me. What about something like this?
Polypropylene Black Woven Stabilization Fabric
http://www.homedepot.com/p/Unbranded-WF2...5-432/204268172My main concern in all of this to prevent grass from growing through over time, leading to constant maintenance.
I like the idea of using larger gravel, then coming back in later with smaller material.