Lawn in a box?

[JamieJ]

Hello,
I live in a building in Toronto and have built something I hope to grow grass in on my patio. It is essentially a box about 3ft x 3ft and about 8" deep, bordered with pressure treated 2x8s and with a plywood bottom. The interior is completely lined with a waterproof 10mm poly plastic sheet.

I plan to grow just some regular (regional) sod I will buy from a local nursery.

1. Should I drill any holes in the bottom of the box to allow for drainage?
2. Should I simply put 6" of garden soil (or would potting soil be better?) underneath the sod or would you recommend an inch or two of crushed stones, for drainage?
3. Any other tips? Are there special precautions for planting sod this time of year (October) in Canada?

Thanks in Advance