Skip St. Arnolds. Most of their beers are quite mainstream, and you wont get any of the good stuff on the tour. For breweries, hit Karbach, No Label, or Southern Star (though thats a tich of a drive, tours only on saturday.) For beer bars, The Flying Saucer is fine, but it is a chain so it's not particularly 'Houstony'. Instead, go to the Hay Merchant or better yet, the best bar in town, The Petrol Station, though the last is a bit off the beaten path its totally worth it.