assuming you're playing Jungle, a general K-Z rune page would probably be:
x9 flat AD reds, to help early clears/ganks
x9 flat armor yellows, the essential for junglers, use these to not die
x9 scaling AP, to protect against mid/late game mages
x9 AD quints, just for more burst
Masteries:
Ferocity
5/5 sorcery
1/1 Doub. Sword
5/5 Vampirisim
1/1 B. Hunter
5/5 Batt. Blows
1/1 DFT (Kha' usually doesn't build crit, and his Q basically replaces his AA's so a bit of scaling DOT won't hurt. Feel free to change it to Thunderlords or whatever because it's the best mastery atm.)
Cunning
5/5 Wanderer (5/5 Savagery if you're more farming centered. I would generally avoid this, however)
1/1 Assasin (1/1 Runic affinity if you plan on camping bot, 1/1 Secret Stash if you're having trouble with clearing)
5/5 Merciless
1/1 Dangerous game
That's what i usually use before going in. If you really want some builds or tactics, you know who to call...
not me because i suck as Kha'zix.[slayer-pantheon-thumbs]