Is a leather saddle appropriate for all-weather riding? In our climate, it rains pretty steadily for 3 seasons. Would a leather saddle (like a Brooks) be appropriate for my bike, or should I look for a different material?
I've used a Brooks saddle in a similar climate (Vancouver, BC) without any major issues.  Treat the topside with Proofide every 6-12 months and keep the underside dry (fenders, wedge bag, etc).  Store the bike in a dry place between rides so that the leather can dry out naturally.  A saddle cover would probably help but I've never used one.