the catalyst 3750-24ts 10/100 ports are numbered 1 through 24. the ports are grouped in pairs. the first member of the pair (port 1) is above the second member (port 2) on the far left, as shown in figure 2-1. port 3 is above port 4, and so on.
the sfp port numbers are numbered 1 (left) and 2 (right).

the 10/100/1000 ports on the catalyst 3750g-24t and 3750g-24ts are grouped in pairs. the first member of the pair (port 1) is above the second member (port 2) on the left, as shown in figure 2-2 and figure 2-3. port 3 is above port 4, and so on. in figure 2-3 the sfp port are numbered 25 to 28.
figure 2-2 catalyst 3750g-24t front panel

the catalyst 3750g-12s sfp module slots are numbered 1 through 12. the ports are grouped in three sets of four, as shown in figure 2-4.
figure 2-4 catalyst 3750g-12s front panel

the catalyst 3750-48ts 10/100 ports are numbered 1 through 48. the ports are grouped in pairs. the first member of the pair (port 1) is above the second member (port 2) on the far left, as shown in figure 2-1. port 3 is above port 4, and so on.
the sfp port numbers are 1 (top) and 2 (bottom) and so on.