I'll be in Toronto for a week starting on Friday. Would love to go to a local brewing co for a few brews and some decent food. Any suggestions? One of my colleague suggested Steam Whistle. Admittedly, I have done no research on local brews. I'll take any and all suggestions into consideration. We'll be staying at the Sheraton.
While Steam Whistle, 3 Brewers and Mill Street are more centrally located and will appeal to first-time beer tourists in Toronto, I'd say a much better, new, unique and exciting experience can be had Bellwoods Brewery. A little heavy on the hipster factor, but great brews and if you sit at the bar great service, and tasty unique snacks.
The Steam Whistle brewery is right downtown, basically at the foot of the CN Tower near the Rogers Centre (formerly SkyDome). They do give interesting tours which include a free beer or two, however, it is simply a functioning brewery and doesn't have a restaurant, so you'd need to eat elsewhere. They make only one beer, a pilsner.
The 3 Brewers brewpub at Yonge and Dundas (Dundas Square) is very central downtown and may be more what you're looking for. The French brewpub chain Les Trois Brasseurs has many locations in France and Quebec and opened this Toronto offshoot a few years ago. They have three standard brews that they make in house, and then one or two special seasonal brews that rotate each month. The beers are decent and drinkable though not super adventurous for hardcore beer fans. The place is large (three floors) and the brew tanks and other equipment are visible throughout. It's boisterous and fun and the menu is varied but unspectacular -- think typical US chain restaurant with a slight European twist. http://les3brasseurs.ca/eng/toronto_yonge.php
The Mill Street Brewpub in the historic Distillery District (about a 10-20 minute walk east from Union Station) is another option. These days they brew most of their beers offsite and only a few in the Distillery, but the pub is very large and it's an interesting area to walk around. I haven't eaten there for a while but in the past I've found the menu to be hit-and-miss. The beer selection is quite wide with a dozen or so varieties available at any given time. At peak hours (such as weekend evenings in the summer) the place can get really busy with tourists so you if you go there I'd aim for a weeknight or something like that. http://millstreetbrewpub.ca/
You might also want to check out places like C'est What (http://cestwhat.ca), the Beer Bistro (http://www.beerbistro.com/) and Bar Volo (http://barvolo.com/) for other very good beer-centric bars/restaurants in the downtown area that are not actually brewpubs. Enjoy!