I thought this had some good points about catch and release:

Catch-and-Release Guidelines

Most catch-and-release research to date has focused on examining species-specific responses to potential factors which affect mortality. However, due to the large number of studies that have been completed to date, a number of general trends are emerging. Thus, while caution should be used when applying species-specific findings to other species, the following recommendations are, given the available knowledge base, general guidelines to be used to reduce catch-and-release mortality for most species.

Angling Techniques

• Circle hooks should be used as they will minimize the chance of deep hooking.
• Barbless hooks are recommended as they are easier to remove and therefore reduce handling time.
• The use of live/organic bait should be discouraged as it increases the likelihood of deephooking.
• The use of artificial lures should be encouraged.
• Fishing lines must not be left unattended as unattended lines have a greater chance of deeply hooking a fish.
• Fishing line used should be appropriate to the species of fish being sought. This will prevent line breaking and reduce playing time.
• Avoid angling during extreme water temperatures, both hot and cold, if you plan on releasing your catch.

Landing a Fish

• Angled fish should be retrieved as quickly as possible to prevent fish exhaustion.
• Where a landing net is required, it should be knotless and preferably made of soft rubber.
• When landing extremely large fish (e.g. muskellunge), the use of landing cradle should be considered.

Handling and Photographing a Fish

• Keep fish in the water as much as possible to minimize air exposure.
• Never place your fingers through gills or in the eyes.
• Don’t hold heavy fish by the jaw as this may damage the jaw and vertebrae.
• Hold large fish horizontally and support its body to avoid damage to the internal organs.
• Use wet hands or wet cloth gloves to handle the fish.
• Have camera ready prior to landing fish to minimize air exposure.
• If possible, photograph the fish while in water.

Unhooking a Fish

• Have longnose pliers available to back the hook out.
• Remove the hook quickly, keeping the fish underwater.
• If the fish is deeply hooked, cut the line and release the fish as quickly as possible.
• Avoid using stainless steel hooks as they take longer to corrode if left in the fish.

Depressurization

• Avoid fishing deeper (5-6 m) waters if you intend to release your catch.
• Consider depth of capture when deciding on whether or not to release a fish.
• Release the fish quickly after it is landed.
• Avoid artificial swim bladder deflation (“fizzing”).

Revival

• If there is current, hold the fish upright, facing into the current.
• If there isn’t any current, gently move fish back and forth in the water until gill movements return to normal and it is able to maintain its balance.
• When the fish begins to struggle, let it swim away.