Originally Posted by bryanp
Just stay away from manhole covers, drainage grates, painted strips on the road because you can loose traction more easily on them in the rain. Get a fender, or complete fenders. Wear a brim somehow to keep the water out of your eyes. That's about all I can think of.
Good advice in all of these posts. Full fenders with a good mudflap will not only help keep the water and grime off of you but also your bike and drivetrain (not to mention any fellow rainy day riders behind you).
As for your eyes, I find that a light cycling cap works great to keep water off my glasses. It's thin enough to fit under the helmet comfortably, and the brim is just the right size---long enough to keep water off my eyes, short enough to see past easily without straining my neck.
My shoes are rather well-vented, which is great in the summer, but lousy for wet days. I cut the corners off a plastic bag and stick my feet in them before going in the shoes to keep them a little drier.
Lots of great advice in the other posts here about riding conservatively... Don't forget to enjoy the ride. (: