how do you build kayle items/runes

The statistics say:

http://champion.gg/champion/Kayle

Though there are specific situations that call for other strategies.

http://champion.gg/champion/Kayle

But if you don't want to go look yourself, my personal build (mind you, I'm mid Gold, so I'm not an authority, but I've spent some time on her) is: Reds- Attack Speed Yellows- Scaling Health/Armor (depending on match-up) Blues- Scaling CDR Quints- Attack Speed

Masteries are 18/9/0, with the Capstone being Fervor.

Nashor's Tooth, Berserker's Greaves, Runaan's Hurricane, Guinsoo's Rageblade, and my last two depend heavily on what the enemy team has/what I need, but Ruined King, Wit's End, Void Staff, Zhonya's, Rabadon's, Guardian Angel, etc. are all items I consider.

Good luck.