Yes, general cleanning specially after rainy ride with gentle soap and water is highly recommended.
Above general cleanning procedure every hub needs to be serviced at least once in six months time (depends on weather condition and mileage).
You need to inspect rim brake surface regularly, making sure that surface is clean and flat (most rims have indicator for wear).
Also check brake pads ocassionaly if there is nothing trapped inside (sometimes little pieces of aluminium can stuck inside rubber compound causing damage to the rim while braking).