Marine fishes and invertebrates use different methods of breeding. There are three maybe four ways. There is the egg-scattering species, egg-depositors, mouthbrooders and pouchbrooders.
The egg-scattering species can be the most difficult to deal with,in this category you will find the Angelfishes and Basslets.
The clownfishes, damselfishes and gobies are known as egg-depositors and their behavior is kind of like the freshwater cichlids. The mouthbrooding jawfishes and cardinalfishes are also similar to the african cichlids.
The marine mouthbrooders present the easiest opportunities for captive breeding. One example of a very popular marine fish that reproduces frequently in home aquariums is the Banggai Cardinalfish, (click on link for pic)
Bangai Cardinalfish photo - Ken Leonard photos at pbase.com
In the case of invertebrates, some lay, or carry eggs, while others simply divide in order to multiply. Crustaceans are often cannibalistic right from birth, making them difficult to rear, but corals multiply readily providing water conditions are just right.
I got this information from the encyclopedia of the Saltwater Aquarium, which I recommend for anyone starting a new aquarium