Hi Reveal1,
At this moment we are looking for experienced FO's which can be upgraded after 6 to 12 months of flying on the right side with us. This means about 4000 hours total experience and about 2000 on the 737 (CL or NG).
If you have less than 1000hours on 737 your chances are dropping significantly for a quick upgrade but you can join as a normal FO and wait to build up the hours.