My first MTB bike.

Just picked up a Marin Pioneer Trail AHT1.0.7 hardtail with Spinner Grind front forks. I have no idea how old it is (maybe a 2010?) and clueless on how to adjust the front forks. I had it tuned up at my LBS and they put a new rear wheel on it.

Can someone give me the skinny on how to adjust my Spinner Grind forks? They are blue with a brass coloured crown. The frame is triple butted, as it says on the downtube. Thanks for any help...