Start by examining every check. There are three: Ne7 (resulting in QxN; forget it), Rb8, and Rxc6. Rb8 leads to KxR, which is of no use to White; here as in the previous example, all White has is his knight, so drawing the king to a square of a different color doesn’t help. But what about Rxc6? As usual, one must actually visualize the Rook on c6 to see all the effects of moving it there. In addition to checking the king, the rook then attacks Black’s queen; so if Black moves his king, RxQ. Black thus has to play QxR. When you picture the outcome of the exchange you realize that it leaves Black’s king and queen on light squares, just like White’s knight; or even without that observation you simply look for your next check and observe that Ne7+ forks Black's king and queen, winning the latter.