Place the salmon skin side down on a large piece of plastic wrap. Combine all of the ingredients for the rub in a small bowl and press onto the top of the salmon. Wrap tightly with the plastic wrap and refrigerate for at least 8 hours, or overnight.
2 hours before grilling, place your cedar plank in a sink full of warm water. This will assist in adding flavor from the plank to the salmon without the wood burning on your grill.
When ready to cook, start your grill and preheat to medium high (about 375 degrees). While your grill preheats, prepare your salmon.
Remove the saran wrap and discard, place the salmon skin side down on the cedar plank. Drizzle the bell pepper with olive oil. Place the cedar plank with the salmon on the grill grate and cook for 20-25 minutes. While the salmon is cooking, prepare your salsa.
Place the bell pepper directly on the grate closest to your flame. The bell pepper will cook for 5-6 minutes, turning it every 2 minutes, until the exterior skin is blistered. Remove the bell pepper from the grill and put it in a zip top plastic bag. Seal most of the top of the bag and let the pepper steam in the bag for 2-3 minutes. Remove the pepper from the bag and peel off the skin, take out the core, seeds, and stem and dice the roasted bell pepper.
In a small bowl combine the mango, bell pepper, cilantro, and lime juice. Set aside until the salmon is finished.
The salmon is done on the grill when it flakes easily with a fork and is opaque throughout. Transfer the cedar planked salmon to a large serving dish and spoon the mango salsa directly on top. Serve with additional limes as garnish.