Just thought I'd share my sources for raw materials in Ottawa.

Plastics
Laird Plastics (http://www.lairdplastics.com/) (they're everywhere (http://www.lairdplastics.com/content/section/16/55/)!)
700 Industrial Av #6 & 7
Ottawa, ON K1G 0Y9
T: 877-228-2296
L: 613-247-9518
F: 613-247-9612
ottawa.lairdplastics.ca
Comments: Usually have to order large 8'x4' sheets. :(

Canus Plastics Inc. (http://www.canusplastics.com/)
300 Lisgar Street
Ottawa, ON K2P 0E2
1-(800)-267-9699
Tel: (613) 232-2657
Fax: (613) 232-6214
E-mail: info@canusplastics.com
Comments: I've never used them, but I hear they can get pretty much anything.

Metal
Loucon Metal (http://www.louconmetal.com/)
37 and 39 Grenfell Cr., Nepean, Ontario K2G 0G3
Near the corner of Slack Rd. and Merivale Rd.
Phone: 613-226-1102
Fax: 613-226-6097
e-mail: info@louconmetal.com
internet: www.louconmetal.com
Comments: These guys are great. They'll take time to cut you a puny $5 scrap. Free delivery on larger orders.

What about Metal Supermarket? Are they worth the trip? I heard they have non minimums or something like that but have never purchased there before.

I used Metal Supermarket while building my Joe's 2006 CNC. Although they have no minimum size they do have a minimum price. All the same they had lots of small odd and I managed to fine all that I need at a fair price. Princess Auto is nearby so it usually makes worth the drive. The best part for me was that they are open on Saturday morning when I can get to them.
Louis

Thanks for the tips especially Loucon Metals same for Laird plastics.

Loucon being open only Monday to Friday hours make it difficult for me.

I generally use Metal Supermarkets as they are conveniently open Saturdays.

I live outside Ottawa in Embrun but work downtown Ottawa weekdays, Saturday is generally my Honey Do and errand day.

cheers, Graham