Note that this is just a recommenden build, feel free to add or dismiss items and their build order in-game. :)
Also, depending on your matchup (ad/ap, squishy/Tanky) and your knowledge of your enemy (if he's going to poke a lot, or play passively), you should start with a longsword and 2 pots (aggressive, for example against Anivia, Annie, evelynn, twisted fate) or with 5 pots and 2 wards (sustain, for example against Cassiopeia, Elise, orianna, teemo, viktor).
Even though some people like to start red pot on zed, I personally do not like this start, since it gives you no ward coverage, and low sustain. For aggressive play style is choose the longsword start, because you can build it directly into a vampiric cepter after your first back.
This is it for my guide, I hope you enjoy it and it helps you on the fields of justice. :)
(I know this is not the standard 10 chapter guide, but I think this is enough to help you in your game, and also whilst mastering Zed, he is not only very fun to play, but he can also carry your whole team to victory :))