Halibut have four fillets.  Two dark and two white.  You'll notice upon filleting that halibut have one long fillet and one short fillet on each side. This is because of the gut cavity.  Also notice the dark portion of the meat.   The dark meat is what tastes fishy and should be trimmed prior to packaging.   Properly bleed halibut will have less blood, whiter meat and it will taste far less fishy.  When packaging your halibut fillets or steaks, do not rinse them with fresh water, use salt water!  The fresh water causes the meat to not last as long in the freezer.  Some fish packagers leave the skin on fillets because they say it prevents freezer burn.  I like the skin off because that's one more thing to cause the halibut meat to taste fishy.  If you think your halibut meat might be on the "fishy" side, simply soak it in milk for an hour.