It looks ripe enough, does it have a little give when you squeeze it? Mangoes go from hard as a rock to rotten in like a millisecond. If it doesn't bounce back from you squeezing it it's too far gone.
In terms of prep, just slice off the edges away from about an inch in the center (that's where the pit is), and do whatever you need to do with the flesh. Dice it to go into something, slice it for whatever, you can even score it in the flesh and drip honey on it, if you're feeling decadent/lazy