Hi, sorry I didn't see your message sooner, I don't visit this site much anymore. I haven't been riding due to sore knees.
If you are looking for some good Muni rides, John Foss would know more than I do. I do know there is some nice trail rides around Jenkinson Lake near Sly Park (Pollock Pines).
Other areas for nice off road rides is the area called the confluence of the American River near Auburn.
http://www.foothill.net/fta/maps/conflu.html
For a long road ride Iron Mountain Rd (also known as Mormon Emigrant trail) is a heck of a stretch. Many cyclists consider it a must do ride.
http://www.chainreaction.com/emigranttrail.htm
For just a nice spin on flat ground the Placerville Airport is a nice flat ride with a nice view. One lap of the airport is 2.4 miles.
For some trials lines I'd try Schnell School in placerville. It's got lots of walking trails and steps and cement benches.
http://www.pusdk8.us/schnell/
