You hold a crooked knife in your right hand (if you're right-handed) with your palm up and with your thumb along the bent part of the handle. You cut towards your body as if it was a one-handed draw knife. The native people didn't have a vice to clamp their work in so they held it with one hand and used a crooked knife with the other.
Here are the awls. The lower one has a triangular blade which is better for making holes in birchbark because it is less likely to split the bark.
The size of the awl you need depends on the thickness of the spruce roots you are using. You want the hole to be just big enough to get the spruce roots through.
Birchbark forms the outside of a birchbark canoe.The bark is used inside out, the white side is on the inside and the pinkish inner side is on the outside of the canoe.
To use birchbark it has to be removed carefully from the tree. You can either cut the tree down or remove the bark while the tree is standing. I am told that removing the bark does not harm a birch tree but it never grows back so I would think it would leave the tree vulnerable to disease.