A good option is a helmet Bluetooth headset like the one I have, a Sena SMH5:
I mainly use it to listen to the directions Google Maps gives me and sometimes music on longer rides. It also acts as a handsfree device for calls and an intercom with other headsets. The dial and buttons are big enough to use with gloves and the controls are pretty intuitive although sound quality isn't the best. I picked mine up for $95. I think a setup like this is better than a dedicated motorcycle GPS unit because it keeps your eyes on the road where they
really need to be when riding. You can also buy helmets with a similar headset built in but then you're limited to having it on just that one helmet and can't transfer it to another helmet if it gets damaged or something. Plus I bought my helmet and this headset for about 2/3 the price of a purpose-built Bluetooth helmet.