Support, mid and solo top build coming...just wanted to share my successful jungle build first.
Because you want to make the most of Karma's passive, you want to stay at low hp while not dying. As you could see, magic resist is already in the build, it is recommended also buy some armor. If you don't have a mana-muncher on your team, and you could freely take blue, replace mana items with more ap (i.e: Rod of Ages).

Start with a safe cloth armor and 5 health potions.
Start wolves, then blue, wraiths, red, golems, then wraiths again, before ganking mid with spirit bonds and red.
Bond your ally and let them run through the enemy, slowing them.
Karma is an exceptionallt good roamer/jungler as she provides heals across the map. And if the enemy jungler catches you, you passive plus heals/shields keeps you barely alive, while keeping them at bay with your bonds. If they're stupid enough to chase, Karma could survive long enough to bait them into your team.
When your wave and shield hit level 4, you could start taking down camps instantly with a q, r, e combo.

Because you want to make the most of Karma's passive, you want to stay at low hp while not dying. As you could see, magic resist is already in the build, it is recommended also buy some armor. If you don't have a mana-muncher on your team, and you could freely take blue, replace mana items with more ap (i.e: Rod of Ages).

Cool down reduction is very important for Karma (for her Mantra), and the items you should get for ap Karma is either Athene's Unholy Grail or Deathfire + Archangel. I prefer the second choice a lot more as Karma isn't a combo champion, meaning I don't blow all my spells in less than 2 seconds (e.g: Veigar), so the cool down on Archangel doesn't matter, and I end up with lots of mana and ability power. I could also give away my blue because of this. However, it does use up an extra item slot, so if the enemy team if full of ad, Athene's + armor (i.e: thornmail) is better.