1. answered by qatarisun

in addition to that, as flor said, you need to send it to Qatar Embassy visa DHL (they know what to do already and knows the requirements) such as:

2 pcs passport size picture
printed visa copy
medical certificate
original passport.

2. & 3. yes, you need to go through POEA as long as it is WORK VISA. it is a MUST. get a schedule for the orientation -- PDOS (do not forget the attendance slip they will give you after!)
Requirements:

a)Medical certificate from an accredited clinic - (you can find the list in POEA)
b)NBI clearance (no, you do not need to authenticate)
c)your CONTRACT is a MUST -- signed by both parties
d)passport copy and stamped visa copy (in your passport)
e)slip/certificate that you have completed PDOS

then, you can pay for the OEC :)