Hi, I play mainly ADC, so here's my guide for Mecha WW. I tried her full PD and hybrid...I don't like it. This guide is up-to-date, but I will edit something from time to time maybe.
Abilities
1.)
GLAIVE STORM (Q) for harassing on lvl 1!
2.)
AFTERBURN (W) to have a fast chance to escape on lvl 2!
3.)
CELERITY (E) on lvl 3 - max it! ...Unless you can skill your
(R)!
This is an ADC guide, so the best thing you can do is to max your
(E) (you need the Attack speed!). Just skill your
(Q) on lvl 1 and your
(W) on lvl 2.
Items
1.) Usually I start with:

+
2.) First item I upgrade to the max:

I like to play with my Katana, cause it gives you a really nice sustain on your lane. You can try to start with it directly, but I recommend Nil Weapon (+Health, Augments lasthit bonus and enough money for three Vials).
3.) Joe Chills' Revolver (1):

If I got a great farm I spend my next 1500 for it. But don't upgrade it to the max directly. First we need more Attack speed! If you don't get so much feed in the beginning go for velocity 9 implants first!
4.) Now get:
5.) Max:
6.) The next step depends...You think you win? You got fcking fed?
Get:

Got some problems?
Vs fed AD:
Vs fed PD:
Not sure? Just get some HP:
This three are still offensive items. So if you got really hard probs, get something else. Fragment of Mogo vs AD for example.
Stolen Powers
I recommend:

If you are new to the role ADC or if you are always to greedy...We don't need Atomic WW's speed, we don't run through enemys, we stay back and have to run away maybe. I recommend:

If you are on a solo lane or your support got no brain...I like Green Arrow's cameras, but you have to farm minions; don't scout wards or something else: