Here is what you do. Go to the Abu Dhabi consulate's web page at

http://www.canadainternational.gc.ca/uae-eau/visas/index.aspx?lang=eng

For a visit visa, go to this page directly to

http://www.canadainternational.gc.ca/uae-eau/visas/forms-formulaires.asp...

Under TRV - visitor, download the application form AND the supplementary application form. Use the checklist for documents required.
Photograph reqd is 35mmx45mm and not the larger one displayed in photo studios -those are for immigration visas. The photoshop guy at the Family Food centre opp the airport is pretty clued in -
The fee is 75 CANADIAN DOLLARS or Dhms equivalent rounded off to the nearest 10 dhms. Exact change is reqd. Dhms is the cheaper option to Canadian $

You have two options - put in all docs plus passport into a strong envelope and have DHL (the ones near Hardees at the airport know the procedure pretty well) mail it to the consulate. The fee is 450 QR each way - 900 in all.

Option 2 - Hop on to the Etihad flight EY 390 that leaves at 4:40am - the embassy is at the Abu Dhabi mall west court 19th floor. Opens 0830. So no other flight for a same-day return is possible as I write. If you have everything ready, submit forms and pay the fee - you are done by 9 am latest. They ask you to come back and collect the passport at 11am. You can expect to be out of there at 1130 - so you can return to Doha the same day.
- PS - if you are a Qatar Airways employee, DHL offers a discount -- Cheers