U will be asked to submit the following things to obtain ur kids Visa.

1. No objection certificate from ur Qatar employer
2. Passport copies of you and ur kids
3. Copy of ur Qatar Residence Permit
4. Birth certificate of ur kids
5. Your marriage certificate
6. Your bank statement for the last six months (Must be with one of the Qatar Bank)
7. Copies of ur educational certificates

All the documents must be attested by ur embassy in the State of Qatar and from the Ministry of Foreign Affairs - Qatar before submitting the documents to the Imigration Department for the approval of Visa.