Homebrew PCBs

Looked through the freeware Eagle 4.16's wirepads library.
Its thirteen thru-hole pads and four SMD pads are more than
adequate for what I'm doing.  

However, in selecting pads for my thru-hole board, I got a couple
questions:

(1)   The numbers......does anybody know what the numbers 
      in the pads library mean?   For example, the smallest thru-
      hole pad is marked 1,6/0,8 and the largest thru-hole pad
      is marked 3,81/1,4

(2)   When I add a pad, do I only add it to the board file, or is it 
  necessary to also add a corresponding entity to the schematic?

Regards,
Alan