You'll be arriving on the island in Friday Harbor via Washington State Ferries (by car or walk-on) San Juan Airlines (from Bellingham) Westwind Aviation (charter flights), or Kenmore Air (from Seattle) or the Victoria Clipper (passenger boat from Seattle), most likely.
This comprehensive page on transport to and among the islands is part of the Visitor's Bureau website.
Once you're in Friday Harbor:
Getting off the ferry, you'll be directed to Friday Harbor's main street, Spring Street. Take it up the hill -- about a mile.
At the yellow coffee drive-through, turn left on Mullis street, and take it out of town (South). In about a mile it becomes Cattle Point Road.
About four miles down, turn left on Jensen Bay Road.
One mile down, turn left again on Halsey Road.
We're second driveway on the left, 259 Halsey Road. The post says "Chadwick" and "Driftwood Farm" and has two reflectors on it like eyes.
Important note on Ferries: this year they've started a 90% reservations policy. They open reservations for 30% of the boat about two months ahead, 30% two weeks ahead, and 30% two days ahead. The 10% is for medical priorities and those lucky few who didn't book but still get on (and that's not many!). So go to Washington State Ferries and make a reservation when you can. Here are opening days for this Summer for the months-ahead window:
April 28 for sailings June 14-30.
April 30 for sailings July 1-15.
May 5 for sailings July 16-29.
May 14 for sailings August 13-26.
May 19 for sailings Aug 27-19.
Even with a reservation, you should try to arrive an hour (or more) before sailing. It's a bother, but should eliminate the 2 to 4-hour waits in Anacortes which were regular hazards of Summer.