The Blue trail is easily accessible, is great for hiking/biking, and has some great views across the lake.
Here are links to the official park site & to a trail map:
http://www.mercercountyparks.org/parks/mercer-county-park
http://www.jorba.org/sites/default/files/2010_SMART_trail_map_0.jpg
When I initially hid this I had started at the East Enterance, but a short way in my bike's chain broke. I ended up driving over here and was able to park right next to GZ, so it's up to you........Do them all in order or come for the quick P&G. The choice is yours.
Bring tweezers and a writing utensil.
ENJOY!