Once in Eldorado Canyon State Park, follow the road for about a mile and park at the visitors center. The trail starts on the hillside above the center. The trail is only partially shaded so be sure to cover up with sunscreen and bring a brimmed hat.
From there, the trail is easy to follow. There are a few little side trails, but they are well labeled. The basic vertical profile of the hike is an initial climb out from the start, then a gentle undulating traverse and, once over the far ridge, back down to South Boulder Creek.
Bring a lunch and water and enjoy!