Off the GTAA site
http://www.gtaa.com/index.aspx
(following the 'getting here & public transit links)....


Pacific Western Airport Express
(Airport to Downtown Toronto Service)
The bus picks up on the Arrivals Level of Terminals 2 & 3, and at New Terminal 1 on the Ground level - post P7. All buses are wheelchair accessible and also have front kneeling doors for easier access. This is a 24 hour service. Destinations include the downtown bus terminal, as well as several major downtown hotels. Connecting service to other downtown locations is also available for an additional fee.
Fee schedule: Downtown to TPIA $14.95 / return-$25.75
Students and seniors receive 10% off one way fares
For more information call Pacific Western Airport Express at (905) 564-6333 or toll free at (800) 387-6787 or visit their web site at www.torontoairportexpress.com.


There is also taxi tarrif map (east map) that seems to indicate the cost of a cab from Yonge/Bloor area is about $43

Anyway, if you follow the gtaa site and 'getting here' link, I think you'll find all the info you need (and some you don't) to get to yyz. Good luck.

DD