Halibut is a great fish! Good choice! Is it a whole fish or is it fillets?
If it's a whole fish, you can roast the whole thing in the oven until it's flaky - I usually put some lemon slices in the body cavity, which add a delicious (but not overpowering) lemon flavor to the fish.
If it's fillets, you can pan fry it (just use a little oil to help keep it from sticking), and just season with salt and pepper - it's very nice just like that.
If you're looking for something snazzier, allrecipes has a bunch of "favorite halibut recipes"... but I tend to like hallibut made simply. allrecipes.com/Recipes/Seafood/Fish/Halibu