Many people probably think Kayle is a "useless champ" or "not even worth playing" but in truth, she is one of the MOST over powered early game champs, and this guide highlights those qualities most. Kayle's base Attack Damage is enough to kill the strongest of champions at level one

Kayle's base Attack Damage is enough to kill the strongest of champions at level one. This is why you should start with a blasting wand and eventually build up to a Rageblade, also increasing Kayle's attack speed which is absolutely necessary when playing Kayle as a damage dealer.
Phage next to increase health; increasing survivability and Zeal to further increase Attack Speed.
Another Zeal for an eventual Phantom Dancer and a Blood Thirster for Life Steal (more survivability) giving you a greater chance to successfully activate your ultimate and beat your foes
The Guardian Angel speaks for itself, giving Armour (Survivability) as well as the revival passive.

Like Alistar, Kayle is not easily countered in Dominion. Usually her <Righteous Fury> (E) ability overwhelms the enemy team at top when fighting for the Capture.
The item build is exactly the same, except get a <Blasting Wand> and <Berserker Greaves> as you beginning items, and replace <The Blood Thirster> with <Sanguine Blade>.
As a frequent Kayle player, the only counter for her that I have played against so far is Darius. His base Health, Armour and AD and Damage on his (Q) ability will probably overwhelm Kayle all game long.