Echo Lakes is only a few miles from my house and, despite the super abundance of hiking trails in the part of the Sierra, it is on of my favorite places in the world.
The trail is a moderately rolling, somewhat rocky trip along the Tahoe Rim Trail towards the Desolation Wilderness. There's an excellent trail guide at the trailhead. Check out the milage to the Wilderness - if you decide that you want to enter it then fill out the (free) permit before you go.
The backcountry views are wonderful but your only chance to see the Lake Tahoe Basin is from an overlook about 500 yards from the start of the trail, following a little climb. The trail is a BIT hard to find for the first 1000 yards or so as many people tramp around that area, creating false trails.
This is a popular trail, winter and summer. Parking can fill up early at Echo Lakes Cabin but there is overflow parking about 1/2 miles back up the road.
The road is closed in winter so it becomes part of your snowshoe/ski trip, too.
Your leash-free dogs are welcome but be sure Rover has good trail manners and be prepared to leash him to pass other hikers if they ask you.
There is a water taxi in the summer that will return you to the trailhead from the head of Lower Echo Lake. The taxi will cut off about 2 miles of your return trip. Also, if he hasn't trained for the rocky conditions then you might want to consider booties to protect his paws.
All Sierra waterways are prone to giardia (aka Beaver Fever) so be prepared to carry your own water or bring a good purifier. Also remember to dress in layers as it can be quite cold in the shade &/or wind, even in mid-summer.