Hold the chip with the pins pointing down and a semicircular "bite" removed from one end of the chip. the first pin on your right is #1. Additional numbering is sequential counterclockwise as:
9 8
10 7
11 6
12 5
13 4
14 3
15 2
16 1
^
To the best of my knowledge, all ICs are numbered this way - including the 555.