Young Hill is a must hike every time we visit San Juan Island. Although considerably lower than Orcas Island's Mount Constitution, I think the views are better--rather than seeing mainland Washington State, you have peripheral views of the entire San Juan Islands and Vancouver Island, and on a clear day, you can see the buildings of Victoria.
You can park at English Camp Visitor parking just off of West Valley Road, south of Roche Harbor. I do suggest you tour English camp, quite a lot of state and national history in the American/English dispute over the San Juan Islands.
Head east through the parking lot to a well-marked trail to begin your hike. Nice and gentle slopes through most of the trail make this hike great for kids or inexperienced hikers. You'll cross West Valley Road and continue up the trail. The hike does get a bit steep in some places the further up you get, but still a great beginner trail.
After an almost 700-foot elevation gain, you're treated to sweeping views of the San Juan Island archipelago--a true gem of the Pacific Northwest. The hike, on average, takes us about 40 minutes with few stops or rests. The hike down went considerably faster, about 25-30 minutes.