I'm on the go so this is going to be quick.
Some people like hiking in sneakers, for me personally I choose more rugged shoes. Your foot's comfort is imperative on a hike. I also always buy waterproof shoes-under no circumstance do you want to hike with wet feet--blisters, blisters, blisters!!!! I have these and I LOVE them:
http://m.rei.com/mt/www.rei.com/product/828400/merrell-moab-mid-waterproof-hiking-boots-womens,-bungee-cord?preferredSku=8284000001&cm_mmc=cse_PLA-_-pla-_-product-_-8284000001&mr:referralID=11ba8290-f6d9-11e2-a969-001b2166c2c0
Also, wool socks to slick moisture away from your feet. I just use the REI brand. And always at least an extra pair. Also, as much synthetic(moisture wicking) clothes as possible, but def synthetic undies... it can get very uncomfortable otherwise.
I can't agree with Romy enough about extra food/water/long sleeve. I bring a breathable rain jacket with me always, it was pricey but wayyyyy worth it.
I also have a paracord bracelet with a whisle and the dog has a paracord collar. I also have emergency fire starter with me always.
2 overlooked(I feel anyway) pieces that I keep in my med kit are vetbond and vetwrap... They're good for more than just dogs!!! LOL. And I always bring a sheet of moleskin.
Another thing to consider is weight, the more you carry the harder it will be on you, buy lighter weight gear if possible.
Ok, my quick second is over! HaHa!!! I have to run! But, I do a fair amount of hiking and started more whole-heartedly on overnight backcountry camping. I you have any specific question feel free to pm me.
ETA: I recommend a good headlamp over a flashlight. If you get stuck hiking at night bc you blow your turn-around time to make the summit you will want your hands free! LOL.