There are a ton of different Mt Tam hikes you can take, four other good ones are listed in the book, 60 Hikes within 60 Miles: San Francisco
I searched a couple sites for a good trail map of the area and found the NPS Muir Woods Map, and the California State Park Map of Mt Tam. Neither of these really show the route very well, but State Park Map is the better one -- its just a bit too detailed and sometimes hard to read.
This hike is a great intro loop hike of Mt Tam, you get some great views of the Bay and Muir Woods. Plus the route crosses a number of creeks and lots of spots of wildflowers (depending on the season). However, if its really foggy some views will be limited.
The hike starts at the Mountain Home parking lot (No fee) which is at 920 feet in elevation. There are about 25 parking spots - prepare to come early to grab one of these if going on a weekend. Be sure to catch the great view from the Mountain Home Inn across the street. (You can also connect with this hike at Bootjack picnic/parking lot further up the Panaoramic Highway- note there is a day use fee at the Bootjack location.)
So after heading north out of the Parking Lot, cross Panoramic Highway and look for the road leading to the Throckmorton Fire Station. There is a three way intersection here -- we took the lower trail (Gravity Car Grade) and quickly wound up going the wrong way. Many thanks to a couple hikers who got us headed on the correct trail. So instead of the downhill trail -- either head on the uphill trail around the Fire station or walk on the road to the Fire station.
The Matt Davis trail has some great views of Marin and even San Francisco when you break out in the open - at least half the trail is in the shade, which is good on hot days. There is one tricky intersection on the Matt Davis trail with the Nora trail. This is a left or right intersection before a bridge. The trail marker has been pulled out of the ground here and was pointed in the wrong direction (we corrected it).
In any case, be sure to turn left and cross the bridge at this point toward BootJack picnic area.
View Mt. Home Parking Lot in a larger map
Basics:
Area - Mount Tamalpais State Park and Marin Municipal Water District
Trails - Hogback Fire Road => Matt Davis trail => Bootjack => Troop 80 => Alice Eastwood Road
Map - Mt Tam State Park Map (ok, but too detailed), Muir Woods Trail Map(shows second half the route)
Length - about 3 miles Loop easy-moderate hike
Trail - Dirt Trail and paved road (for a short part)
Dogs - Not on all the trails
Bikes - No
Views - Views of Muir Woods, San Francisco, and Tiburon in a couple spots
Getting There (Car) - US101 North, Exit the Highway 1 Mill Valley/Stinson Beach), Follow signs for Highway 1 north, Turn right on Panoramic Highway (look for Mt Tam sign). After a twisty 2.5 miles, you reach the Mountain Home Inn -- the parking lot is on the Left.
Getting There (Transit) - You can take Marin Transit Route 61 from Marin City to reach the Mtn Home Inn (Panoramic & Edgewood). Note this is a small bus and runs about every two hours during the weekend non-winter season.
Fee - No fee at this parking lot - but it will fill quickly on weekends
Weather - A few open sunny spots, otherwise almost all in the shade
Other Trails - Lots in the Marin Municipal Water District's Mt. Tamalpais Watershed, Mt Tam State Park and Muir Woods National Monument
Facilities - restrooms at the Mtn Home trailhead/parking lot - there is also a restroom at the Bootjack picnic area