As a SAR member, I just want to let you all know that the most fatalities come from "day hikes". Most people do not bring what they need in case something, anything, happens.
Bring a dry set of clothes wrapped in zip locks
Signaling device, glowstick, strobe, flashlight, etc
Space blanket
Backpack, used for you stuff and as a sleeping bag
food
water
compass
water purification tabs
There are a few others but those are the most important. The best thing you can do is let your friends and/or family know where you are going and when you are supposed to be home. You should also leave an itinerary in your car where you depart from, it is a great resource when (if) we have to go looking for you.
Oh, best tip, have a great time! My suggestions are in case of a worst case scenario, which do happen, but not often. Be safe and have a blast...