Dear bro, kindly followup the below process:

1. Salary Letter from Employer (Arabic - Typed and addressed to MOI-Immigration Dept) - Contact your PRO of Company.
2. Copy of Your passport and Work VISA Page
3. Copy of your Education Certificate (ATTESTED - See Below for attestation details)
4. Wife's Passport Copy
5. Marriage Certificate (ATTESTED - See Below for attestation details)
6. Child(s) Birth Certificate(s) (ATTESTED - See Below for attestation details)
7) rent agreement duly attested by muncipility (muncipilty shall require another set of documents like copy of title, copy of owner QID, lay out, etc. for stamping)
REMEMBER - FOR EACH INDIVIDUAL ENTRANT APPLICATION AND DOCUMENTS SHOULD BE SEPERATELY ATTACHED.
FOR ATTESTATION:
Following attestations are required on the Originals
1. Notarization (NOTERY) from Magistrate or your home country
2. Ministry Of External affairs from your home country
3. Qatar Embassy - in your home country
4. At the end - Ministry of Foreign Affairs (MOFA)- in Qatar
I think this link will give an idea about attestation-website:http://sheenservices.com/contact-us.html