How well does a bow stand up to water/rain, and what do I need to do to care for my bow if it gets wet or I opt to hunt a rainy day?
Any modern bow should handle getting wet just fine. I've never done anything for my bow after being out in the rain/snow. It has some rust on the various bolts but it works just fine.
Dry it off if it gets wet and lube the cams, axles, and bushings and wax the string at least once a year.
I wax the string multiple times each season. Around 3-5 times. I always dry off the bow and wax the string after i've been out in real wet weather like steady rain or sleet/wet snow. Just make sure it's dry before you put in the case and wax the string and it'll be fine.
Not a fan of WD-30 for bows due to the odor. Most newer bows have sealed bearings. A properly waxed string should prevent water penetration.