I'm new to mountain biking and I love it. I live in San Diego and I'm looking for some new trails. I've done the Miramar Lake trail and the Lake Poway trail. I prefer something going around a lake and is often used. Not too hard and not too easy.
i dont know about san diego but there are some amazing ones in orange county, you can also pick up a map with camps with tracks for biking at welcome centers for free, its how i got around