If you're riding in Pisgah proper, but you want to break in your newbie friend/partner/kids gently, then take them on a run down the lower section of Spencer Branch trail. This piece of Spencer Branch winds gently down through a little valley, surprisingly smooth, with plenty of small rooty hops and creek crossings to keep it interesting. Some of the creek banks are guarded by tough root lacing, and the log crossing over the creek is enough to make anyone sweat. It's a sweet little 2-mile slice of true Pisgah singletrack, and its only fault is that it's over too soon.
From the popular Trace Ride trailhead, set off along gated forest service road FS 5097, the Never-ending Road. After about 4 miles winding through the forest, a signed entrance for Spencer Branch will appear on the right, heading up the mountain: this is definitely not the section of trail you want. Keep going another ½ mile, and you'll find a second sign for Spencer Branch and a clear trail dropping down to the left. That's your ride.
Spencer Branch eventually brings you out down by the old Hendersonville Reservoir, and from there it's an easy 1 mile pedal back up to the trailhead. Spencer Branch does intersect with several other trails (Middle Prong, Fletcher Creek, Big Creek), but they're usually clearly marked, and they all end up at the reservoir in any case.