I want to add some light fixtures in the attic, how do split off electrical wire there?

I want to add 3 simple light fixtures in the attic. I know I will need a junction box, but how exactly do I do this safely and be in code? Please advise.I want to add some light fixtures in the attic, how do split off electrical wire there?
first identfi the wire and where it goes. next turn off breaker for that line (if not sure turn off main breaker). cut wire (wire must have some slact to pull into box). box must have a cover that can be shut,must be mounted to a joise or rafter. use wire nuts to splice you wires together(white to white,Black to black,ground to ground). repete for each light. don't for get to have a swich some where in the chain. their are good books you can findI want to add some light fixtures in the attic, how do split off electrical wire there?
pick a line with not much on it, kill the power to that line use a current tester to make sure the power is off,cut you`r feed wire strip back the casings pull the wires in to an electrical box threw the knock outs twist you`r 3 sets of wires together (clock wise) screw on your merrets %26amp;tape them to for good measure install the cover plate. the 3 sets of wires are the feed the attic light %26amp; the light or plug that you cut off the feed line
I know it's not what you want to hear, but reality bites: unless you're a journeyman electrician ( and I am not one of those), you'd better hire the job done. Screwing around with wiring can get ya killed, and death is permanent!
if your not sure how to do it then dont try it. maybe with a friend that knows a thing or 2. At least shut the power down before you attempt it.