Hey, being from Halifax, it seriously depends on what you want to do. You can hit up the citadel, but only tourists go there. The locals don't go. I haven't been there in 20 years. Good for a look of the harbour though. If you want to party, definitely hit the Lower Deck. Maritime music, total mixed crowd of young and old, guaranteed to have fun and I think it's the oldest pub in NA. Also the most famous bar in Halifax. To start out your night, hit the Shoe Shop. The most unique and coolest bar in the city. It was my home away from home and a very popular spot. Also, try the Pogue for pub/dancing. If you're into big clubs, do the Liquor Dome or the Palace. I avoid those places like the plague though. Crowd is way too young. Lots of under-agers, so check ID's! Maxwell's and the Ale House will give you 2 of the biggest selections of beers around. Another great place to start out at is The Bitter End or the Fireside. Great martini bar's, cool atmospehere's.
To eat, My brother Darrell's (best peanut butter burger you can find) and chicken wrap, Your Father's Mustauche (pub food), Five Fisherman (high end good seafood). My fav lunch spot was always The Argyle....more because of the waitresses.
Definitely check out the waterfront. Do a boat cruise. They even have licensed boat cruises at night. Good way to start out and then you can walk anywhere from there. Halifax has the biggest bar per capita of any place in NA, last I heard.
Heading up the Cabot Trail, make sure you head up on HWY 19 along the coast when you get onto Cape Breton. You see the ocean for most of it and go through lots of small towns along the way. Port Hood, home of Al MacInnis! Takes about 3.5 hours from Halifax to get to Cheticamp. Stay in Cheticamp first. Get a waterfront chalet at the Pilot Whale or something. Beautiful little Acadian town. Definitely a throw back. From there, you can take a whole day just driving around the Park. Stay in Ingonish. My fav part of the park. World famous golfing, really nice beach. I would own land in this little town if I could. Go to the Thirsty Hiker Pub for wicked celtic music....and last time I stopped in there, a female soccer teams decided to swing in for the evening. Oo la la! On the way back to Halifax, hit up Baddeck. Another beautiful town on the Bras D'or lakes!
Also, when you get to Halifax, you want to do a beach, hit up Rainbow haven. Awesome sandy beach. If you're a little more adventurous, go to Crystal Cresent. Every more beautiful, crystal blue waters, white sandy beach....and nudists
Mostly old dudes though, so don't get too excited. If you're bored and want a cool hike, do Duncan's Cove. 1.5 hours one way along the mouth of the harbor along huge craggy rocks. Well beaten path. Watch ships come in.
CHeck out the Museum of the Atlantic. The best Titanic display. You can see parts of the ship. Not sure which town your brother lives in. If it's Truro, that's where I grew up. Pretty lazy slow town. You can see the Tidal Bore (The tide comes up and pushes the Salmon River in reverse. pretty neat) If he's in the valley in Wolfville, way better. The valley is beautiful. Hit up a vineyard or 2. Stutz is a good one just outside of Wolfville. You can also get a great experience with the tides at Scot's Bay. If you get time, hike Cape Split. One of the top 3 hikes in the Maritimes. When you walk out to the point, you stand a top a giant cliff looking over the Bay of Fundy. Watch the tides come in there. Super sick!
Anything else, PM me. I know the whole province like the back of my hand. I traveled for like 7 years for various jobs and I've seen everything.
Mike