Of course, even before you hit the trail, your Lab will need some prep work just as you doparticularly if you're talking backpacking. If so, then you'll want to take the dog on day hikes of increasing length (assuming you haven't done so already). His muscles, lungs, and heart all need to adapt to the extra work, just as yours do, plus it'll give him a chance to toughen up his paw pads a little.
As far as packing stuff for the pooch, I'm not sure a Lab really needs any extra clothing," unless you're going out in unseasonably cool or cold weather. Several companies make dog overcoats that can keep his back dry, and therefore warmer. An example: Ruffwear's K-9 Overcoat ($72 for one that's Labrador-sized; www.ruffwear.com). On very rocky, difficult terrain, the dog may also need some booties to protect his feet. Paw Pals Dog Booties ($16; www.greatoutdoorsdepot.com) handle this task nicely.
But, what about sleeping arrangements? Well, one good choice is to pack a Ruff Wear Mutt Hutt ($90 for large size). That's righta tent for your dog. If he's accustomed to sleeping on his own, not in bed with you, he might take right to it. For added comfort, pack along as well a Camp K-9 Trail Pad from Cascade Designs, which comes in several sizes and styles (www.cascadedesigns.com). I don't think it would hurt to pack a small fleece blanket; Labs have sorta short coats, of course, and a little extra warmth might be appreciated.
If you're not too much of a bleeding heart, a big dog like that can handle carrying some of his own gear, toocertainly his food. Dog panniers are handy things, something like the Wolf Packs Trekker ($54; www.wolfpacks.com).
You're almost all set to go, but one concern worth keeping in mind: He gets up at night and goes prowling, never to return. You'll need to figure out some way to leash him in place, or connect a length of cord to a nearby tree and tie one end to his collar (provided he can't go over a cliff and hang himself). And, ticks are a worry as well. Treat him with a tick repellent before departing, and with a tick killer or repellent after you get back. Some of the newer repellents that are applied to the nape of a dog's net, such as Frontline, work well.
Otherwise, have a great time!"