Chimney Top is a spur trail off the north end of the North Fork Mountain Trail. Parking at the trailhead is limited to 8-10 cars. Get there early on a nice day. The trail is blue blazed, and it is easy to follow. It climbs steadily for about 2.5 miles. The footing is a combination of dirt, large, and smaller rocks. Most of the time it requires your attention. The spur trail is on the right. There is a cairn at the intersection of the Chimney Top spur. It is hard to miss. This spur is short and quite steep.
No matter what I write, it will not do this hike justice. I encourage you to make the effort to visit this area. Here are some helpful links.
First, for more information visit Spruce Knob - Seneca Rocks National Recreation Area website.
Next, Hiking Upward also has a great description.
Finally, please don't confuse this with Chimney Rock State Park in Maryland!