is a great site, not only for fasteners but they have .pdf files that tell you anything and EVERYTHING you need to know about fasteners. Click on "fastener info" on the top right on the webpage and enjoy!
Tap them into a predrilled hole with a hammer or a punch with an indent in the end to fit the radius of the head. They are not used in a structural situation like a screw or bolt. More like a small nail to hold something, a nameplate, onto a metal surface.