How should I install a vent surrounded by my roof? I'm installing the basic vents. Should I drill a pilot hole first...

I'm installing the basic vents. Should I drill a pilot hole first from inside the attic? How should you stir about taking the shingles off, anything to watch out of? Thanks, just wanna make sure I do it right the first time.
Answers:    you can drill a hole or drive a staple..I started using my nail gun..I use a jig saw or sawsall.as far as the shingles go.cut the hole first only a little big.and lay the flashing right there and look at it.that will recount you how to cut and slide under the roofing...you need to take down at least one layer, sometimes two.next caulk or tar around back and anything to be exact obvious...good luck steal your time..till you get the idea..after that it will dance quick...nite
saws adjectives ? don't push the shingles up when you drill,let the drill cut them.and the saw maybe screw a piece of plywood from the center over them.afterwards make your cuts form the out side After you drill,starting holes.so it lines up between rafters and not on.