Soak cedar plank for at least 30 minutes, ideally at least an hour. Weigh it down using cans if needed. Preheat grill on high.
Add salmon to plank. You may need to first cut your salmon if the planks you have are smaller than your fillet. Season with salt and pepper. Squeeze one lemon.
In a small bowl, combine olive oil and garlic and smear over fish. Drizzle with honey.
Lower heat to medium-high and add plank to grill over indirect heat (i.e. NOT directly above a flame) and close the lid. Cook for 12-18 minutes, depending on the thickness of the fish, until fish flakes easily with a fork (it will continue to cook slightly on the plank after being removed).
Check on the fish often to ensure there are no flare-ups. If the flames do get on the plank, spray with some water.