The journey starts at Bear Lake trailhead and it continues uphill to Nymph Lake and then on to Dream Lake, and ends at Emerald Lake. It is not an impossible climb, albeit my wife and my 6yr old had to make a few stops along the way to catch a breather before marching on uphill. The hike up is definitely very rewarding when you arrive at each lake to take in the scenery and serenity.
You'll run into a lot of people along this trail especially on the weekends. That was our experience at least for the Sunday that we hiked this trail.
I suggest you take a few snacks, or even pack a light lunch. That way, you can fill your tummy with some grub while you take in the view at each lake. Oh yeah don't forget water, water, water.
We spent about 5 hours on this trail, due to the many photo op stops and grub time, (not forgetting the "pit stops" for breathers).
We enjoyed Dream Lake the most, because that's where we had our packed lunch and dipped our feets into the icy cool lake.
By the way, this trail is a lot easier on the return trip, simply because its downhill! Less stops and arrived at Bear Lake trailhead in about 30~40 minutes from Emerald Lake (we made a stop at Nymph Lake, and of course a few photo op stops as well).