I usually get my gesso from Dick Blick. I spray the canvas with water first, and also water down the first coat, to get good coverage and adhesion. Then I go heavier with the next one to two coats.
When I gesso the canvas, I leave the sides alone. The gesso and later paint will sometimes intrude over the edges a little, but for the most part, the sides stay naked.
I side with the Minimalists on this issue...I like to reinforce the object-ness of the painting--it's a thing, not an illusion or a pretend window to the world. Covering the sides is like saying, "Pay no attention to that man behind the curtain!" The viewer should be able to see what's behind the paint.