An actual flintlock, or did you mean just a black powder rifle?
Here's a link to some flintlocks on Midway if it's the former:
Midway USA Flintlocks for sale
I've never hunted using a flintlock, but I imagine it's similar to a regular smokepole. Modern inline muzzleloaders are easier to shoot, clean, and maintain, so keep that in mind. The tools you'll need are as follows, and links to see what they are. These are just what I use/have used, you can play around with all sorts of stuff, but here's the basics:
Inline rifle: I'd use a CVA Optima or Thompson Center
Link
Bullet starter and ramrod: The rifles usually come with their own ramrod
Link
Powder: Up to you, but I use Pyrodex pellets or 777 Pellets
Link
Bullets: Hornady sabots have worked better for me than Powerbelts. It's up to you to get the high speed sabot-on-a-stick which makes loading faster
Link
209 Primers Link
Speed loaders: Link
Cleaning gear: Dawn dish soap, hot water, rod, brush, patches, and finish it off with a CLP laden patch, followed by 3 dry patches to ensure you get the oil out while still leaving the bore protected.
Breech plug grease: Sold at most sporting goods stores
Ammo can/Dry box To store your goodies
Here's a tip also, when you get your rifle, after you clean it the first time, drop the ramrod into your gun and wrap a piece of 100mph tape or etch a line on the ramrod where the exposed rod meets the muzzle. This will help you determine whether the rifle is loaded or not.
Then, when you get to a range/shooting spot, load the rifle, ensure the bullet is firmly seated, then tape/etch where the rod meets the muzzle so you know what right looks like. This is beneficial especially when reloading hastily to drop another deer, or in case you missed and the bewildered critter is still standing there for another try.
A trick I learned from my stepdad to make sure the bullet is properly seated, is to get the ramrod to bounce. It's hard for me to articulate, but you ram/drop the rod into the barrel several times at a good rate of speed after you THINK the bullet is seated, but not fast enough to damage the sabot tip. You start with the rod halfway down the barrel, then use the rod like you'd throw a dart is the best way I can describe it.
I'd also like to recommend that when you're done hunting for the day, discharge the rifle. I hope this helps a little, and I'm sure as I was typing this, someone more experienced than me chimed in. Good hunting!
***ETA***: I just read PA's hunting guide, and found that they actually have a separate Flintlock season...
The way you stated "black powder" later in your post led me to believe you were using the term "flintlock" in lieu of "muzzleloader". Mea culpa!
Some of the info I posted is still relevant however