When you ask about reef fishing I am assuming you refer to bait fishing over a reef. This is a very popular form of fishing in the southeastern waters of the Atlantic Ocean and the Gulf of Mexico.
The first key is to find the reefs, there are certainly many of them available. A depth finder certainly aids in this effort. You can also purchase maps that will give you gps coordinates of many of the major reefs.
Like all forms of fishing there is nothing one hundred percent constant about reef fishing. A particular reef may hold many fish one day and not very many another day. The major reefs however are much more reliable and generally always hold large amounts of fish.
Another prime consideration is the weather, mainly the wind and direction and speed of the current and tide. You need to be able to keep your boat over the reef and you need to keep the boat steady enough to fish comfortably and successfully. This is a matter of experience fishing the water you are near.
I do not suggest renting boat and fishing reefs over unfamiliar waters. Reef fishing is for experienced captains, hire a guide in waters you are not familiar with.
The equipment you use will often make or break a reef fishing excursion. You absolutely must have a very stout heavy action fishing rod if you plan to catch anything of decent size. A free spooling trolling reel is preferred but you can get by with spinning gear. The reel must however be able to hold amounts of heavy test line. I recommend using braided line when reef .
Braided line offers three very important advantages for this type of fishing. First braided line is much more abrasion resistant than monofilament lines. Your line will constantly be brushing against the reef and needs to be strong. Secondly braided line is much smaller in diameter than monofilament line of the same weight class. You can fit much more line in a reel; a very important factor is reef fishing. Finally braided line has much less stretch than monofilament line which as you will learn later is important.
Your rig should consist of a large egg shaped sinker slid through the line. Attach a strong high quality swivel to the line just below the sinker. At this point you will use a leader of about twelve to twenty four inches. Attach a large hook to the rig and you are ready to fish. It is wise to have several rigs premade as you will often need to switch out rigs that have become frayed or worse yet broken off.
Reef fishing is done at of near the bottom, depending on which species you are attempting to catch. You should release your line until the sinker reaches the bottom. Then you generally want to retrieve your line so the bait rests a foot or two off the bottom. You can use a variety of baits.
Live shrimp, crabs, mullet and a variety of other fish work well. In the absence of live bait you can also use cut pieces of fish with amazing effectiveness. Just make sure the cut fish is fresh and not frozen or rancid.