I just recently brought my wife and son here in Qatar. All u need to do is send the copy of visa, Marriage certificate (NSO), NBI, birth certificate (NSO) and Medical results to Qatar Embassy via DHL. The documents should be the original and a photocopy. If I am not mistaken they charge Php700 per person. They usually return the documents with the certification after a week. The price might be a little exepensive but at least u dont have to experience the same process I went through where u have to fall in line at the gate of Dasma Village early in the morning.

The process could be tedious but its all worth it once your here.

Regards.