Howdy Steve,
I used to manage at the Sail and Anchor back in the America's Cup days! Another pub is the Norfolk or, 'Norfolk and Worries,' as we used to call it, which is 200 yards south of the S&A. Nice pub and probably still has good beer. Try to visit on Fri-Sun as the Fremantle Markets are open then. Both are Matilda Bay pubs.
Also from there if you head towards the water and cross the railway line (5 minute walk) you'll find, 'Fishing Boat Habour,' where, 'Little Creatures,' (mentioned above) is based. Certainly a unique pub/brewery and worth a visit. Lot more to see around that location as well.
Now, let's get on to the only topic more important than what beers to drink...
WA has the highest per capita population of good-looking women I have ever seen. You'll probably not want to take my word for this so go to...
The Left Bank (Saturday night or Sunday Arvo)
The Cottesloe Hotel (Beer Garden - Sunday Arvo)
and you'll see what I mean
The tap beer is lousy but you won't be worrying about that too much will you?
If you are an hour down south, go another hour (probably a bit more?) to Pemberton and Margaret River. Beautiful countryside and atmosphere. Climb the, 'Gloucester Tree,' in Pemberton and post back here to say that you drank a beer at the top for us!
You'll have a great time.
Cheers
PP