CD-R Duplication is perfect for short-runs up to 500 units, or even more if you don't have time for CD Replication.  Standard turn times for Duplication are:

         < 500 units = 1 - 3 business days
  500 - 1500 units = 2 - 4 business days
1500 - 5000 units = 3 - 5 business days

For an in-depth look at how CDs are made: http://en.wikipedia.org/wiki/Compact_Disc