On the sites to see question, I usually take visitors to Inspiration Point, make sure you stop at the wood map so you can sea where all the mountains are. This is pretty much the beginning of the San Gabriel River. In addition, if there's no marine layer you can see the ocean, ships at see and Santa Catalina Island but the view is spectacular nonetheless. This is just up Hwy 2 from Big Pines ANF Visitor Center.
Further up Hwy2, a great place for all but especially kids, is the Grassy Hollow ANF Visitor Center. There are LOTS of interactive stations for the kids and stuffed creatures including a bear, mountain lion and bobcat (previous car fatalities, fyi).