there are lots of yummy ways to cook fish that are healthy
My favorite is steamed salmon with bayleaf, lemon and garlic in the water. Try it brushed with a little brown mustard... total yumminess. I once had this mustard salmon over wilted garlic spinach at a restaurant- fabulous.
Really, just play around. Use fairly low fat ingredients and experiment. A lot of the spice bottles will say right on it if they are typically used on fish
There are lots of good healthy recipe sites out there: eatingwell.com, allrecipes.com (they have a healthy section) and even the Food Network's website has a bunch of healthy recipes. Fish is great because most varieties are mild, so you can dress it up in a million different ways, with all sorts of flavors.