As I have previously posted, shark fishing is not really my thing. Where I live sharks are considered something of a pain when reef fishing, but I understand that sharks are a very popular targets in other parts of the country and indeed the world.
Catching sharks
The key to catching sharks can be found in one word chum (also called berley or ground bait) and lots of it. Sharks have relatively poor eyesight, but one of the best senses of smell of any animal. A large majority of a sharks brain is dedicated to smell and research suggests sharks can find food by smell alone from kilometers away. Some popular forms of chum for shark fishing is tuna chunks, small baitfish, tuna oil, chicken. Some people blend/mince all their fish frames up into old milk cartons and freeze the mixture to use. Best results are usually found when an angler creates a chum slick, which usually includes mixtures of fish oil and fish bits added to the slick in a consistent manner. Chum can directly be thrown into the water or added with the aid of a chum dispenser.
What you need
Sharks will make short work of low quality tackle and shark fishing requires top quality tackle. Most anglers use 50-80 pound mainline with a 200-300 pound leader usually made of wire to prevent bite-offs. A wind on leader is a very good idea! Hook size is usually between 10/0 - 12/0 and strong hooks are a necessity. When targeting smaller sharks you can get away with hooks down to about 3/0 in size. A fighting belt and harness is also a great idea when shark fishing.
Bait for sharks
Without wanting to make this sound too simple - Sharks eat fish. Any fresh fish flesh will do and tuna is one of the most popular.
Remember shark fishing can be dangerous. Always prepare well before tackling the biggest shark species. Always check local regulations when targeting sharks.