Well, I have mixed feelings about this trail. The woods and wildlife are awesome, but the trail itself is tough on the bike. The sand/salt really chews up the chain, rims, derailleurs -- basically anything that moves.
The easiest way in is to take 395, which runs between HWY 98 and HWY 30A (near Seaside and Seagrove) and enter the trail on the east side of 395. The trailhead is about halfway in between 98 and 30A. From there, you have three loops that you can pick three routes: a ~3 miler, a ~5 miler, and a 10 miler. These trails are easy and open, much of it is on the service roads (hard pan, sand). The offroad trails are covered with mulch and loose sand and gravel -- some places are hard to traverse unless it has just rained. The long loop takes you by the Eastern Lake, and is scenic to ride. All of it is quite flat. I took my ten year old on the 5 mile loop and he didn't have too much trouble navigating it. I would advise early morning during the summer. Late afternoon is not bad, but the mosquitoes come out in droves in the evening.