This kit is available at various cycling and sports stores, as well as on Amazon for less that $14. It is a good size, contains the basics, and has room to add extras.
Recommended supplies for a small first aid kit for cyclists:
Most of these items can be found at your local Pharmacy, or at Ontario Medical Supply, 1100 Algoma Road, Ottawa. Another alternative source is to buy one of the large medical kits at Costco, usually in the $35 range. They have enough supplies to make 2 or 3 kits, with lots left over. Most of this can fit in a small sandwich size baggie, or you can opt for a dedicated pouch like this one on Amazon.
The following items are optional, but you may like to include some or all to fill out your kit.