Welcome!

I have been reading and using various guides here on mobafire, now I'd like to share my thoughts on the new champion who just arrived in the League, Karma.

Please rate, and send me some feedback.

I've chosen to go with the usual caster masteries 9/0/21, this will allow to get some early CDR and damage.
Another good choice should be 0/9/12 with 3 points in Hardiness, Resistance and Strenght of Spirit, so you are some more resistant and regenerate some more mana.

The same with runes with Magic Penetration marks Mp5/lvl seals and ap/lvl glyphs, I choose flat AP quints for an early help in doing damage/absorbing damage/healing, but Quintessences are really up to you.

(Note AP ratios are missing as I don't know them at the moment they will be upgraded as sson ai I know them)

PassiveInner Fire Karma Gains up to XX/XX/90/130 Ability Power correspondin to her % of missing Health.

(Q)Heavenly Wave: Karma sends forth hidden blades from her fans, dealing 70/110/150/190/230/270 magic damage to units in a cone in front of her.
Mantra bonus: in addition to dealing damage to enemies, Heavenly Wave will also heal allies in the cone for 30/45/60/75/90/105 plus 5%+(AP) of their missing health

(W)Spirit Bond: Karma creates a beam between an ally or enemy for up to 5 seconds. Allied anchors move 10/12/14/16/18/20% quicker and enemy anchors are slowed by 10/12/14/16/18/20%. The beam deals 80/125/170/215/260/305 magic damage to enemies and applies the same movement speed adjustement anchors receive to any champion ti passes through.
the beam breaks if the bonded target is stealthed.
Mantra Bonus: Karma strenghens the bond to dobule the effect of the movement speed modifier.

(E)Soul Shield: Karma summons a protective shield that absorbs 70/110/150/190/230/270 damage for 5 seconds
Mantra bonus: In addition to casting the shield dealing 70/110/150/190/230/270 magic damage to enemy units aroung her target

(R)Mantra: Karma empowers her next ability with an additional effect. Karma gains a charge every 30 seconds up to 2 charges.
The refresh rate is reduced by Cooldown Reduction.

Your Ultimate gives you this second resource to manage, keep an eye on the buff monitoring how mmuch time is missing to the next mantra stack.
I'll use Mantra-Q/W/E to mean that I'm using my Ulti to empower that specific Skill.

I decided to max first Q then E for a few reasons:
Q in great to push the lane, harass or last hit many minions on low health, it's also only your only heal spell.
E can deny your enemies quite some damage if used well, also it's good fo it's synergy with mantra which will mate i also do AoE damage equal to it's shield and it's castable on (allied) minions.
Your W it's somewhat tricky to use but generally you should put it on a target that makes it so that the beal will pass though the most enemies/allies without endangering yourself too much.

Generally I tend to use mantra (R) on my Q or E, but if the situations calls for it don't hesitate to use it on the W for increased movement/slow.

Remember Mantra scales with CDR it has a recharge time of 30seconds per karma and you only have two stacks of it to use; with maxed CDR you lower this time to 18 secs making it much more "spammable"

As to summoner spells I choose ghost and flash:
I wanted to maximise my survivability.
Ghost is very useful for those situations where you need to be in another place and be there fast, be it following a low health runner or trying to escape the enemy team angry at yyou because you have just destroied their tower!
Flash is another gank escaper, and one of the best!

Other good summoner spells could include clarity for the ealry game mana regen, exhaust for the slow and the -% dmg done, teleport to get to the pushing/pushed lane quickly (remember to take the mastery!), cleanse if the enemy team is REALLY HARD on CC, clairovayance (if you know how to use it well it make it another gank escape/scout spell)
summoners spell I wouldn't recommend are things like rally (seriously does anyone ever take it?), fortify, ignite (you are a support you shouldn't get this but if you really wish to...), smite (Karma is a good farmer with her Q and mantra E you shouldn't worry about it unless you want to jungle which isn't the point of this guide)

My items choice is made so you can reach easly the CDR cap, and still get a good survivability while being able to use her passive efficiently and not fall off too much on the AP.
Why I didn't choose more AP oriented items to get?
Well with her passive granting ap when her health is low, the more the less you have up to 130 at level 18, and her base damage/heal being quite high enough with decent scaling I found myself ok with it, remember the less hp you have the more deadly you can become (and the more your Q heals you)

I usually start with a Doran's Ring, it gives that tiny bit of everything you need and helps her survivability.

Mercury Boots are usually the best boots in many matches due to the quantity of CC present, if the enemy team is very low on CC you could get Sorceres Shoes or the ones you like the best(Berserker Greaves are rather useless on her thou).

After you got your shoes i usually get a tear of the goddes so it can begin to stack the maxmana unique, if you are seriously harassed and might need survival get first the Rod of Ages out, it will max out sooner and will make you harder to kill.

Get your Rod of Ages if you didn't already, or the Tear of the Goddes whichever you haven't bought just yet.

Get your Kindlegem for the Spirit Visage, it's a rather good item on Karma it makes your mantra-Q Heal yourself for more, gives health and CDR and it's really cheap!

Another good item wich is also usefull for everyone near you is the Soul Shroud, +HP for you and 12mp5 and 15% CDR for you and your allies, WONDERFULL!

Now should be the time where you can upgrade your tear into an Archangel staff.
The last item you can get instead of the doran's ring it's rather up to you, you can get some more survivability if you're targeted too much, or more AP to do even more healing, shielding and damage.

Remember to grab often the blue buff so you max out the CDR early and can spam skills and mantra a LOT.

If the enemy team hasn't many CC or they they have a champion who can easly be disabled by a Banshee's Veil I suggest to get Ionian Boots of Lucidity and the Banshee leaving out Soul Shroud off the build.

In early game you should harass the enemy laners, and protect yourself and your laning partner fro harass.
Use mantra to heal and to make your shield damage them (remember it's also castable on minions!).
Try to not keep yourself too much dead nor too much alive so you can benefit from your passive, be wary of your enemies and don't fear to back up/Q-heal if you feel in peril.
Try to last hit, and to not deny too much from your parnter.

In mid-game you can, and should be helping you allies pushing and defending, Karma is rather good at eliminating an enemy minion wave accumulated to your tower with Q + mantra-E, you could also use W on the furter minion so all of them get it by the beam (and be damaged).
In teamfights mantra-Q in the fray so you damage enemies and heal allies, mantra-E is another good combo to do on a melee champion: you shield him/her and meanwhile damage all close enemies. Mantra-W only if you need to seriously stop an enemy from fleeing or need to boost your carry/team to a location extremly quickly. At this point you should be always aware to use mantra well unless you have the blue buff and enough CDR to get to th 40% cap.

Now comes the late game, you aren't so squishy that you don't need to be too far away from the fight, you should have 40$ CDR without the blue buff (remember to buy your blue elixir) and you can spam mantra much more. Now Spirit Bond can get an almost 100% uptime now and should almost always be on cd, so your team will move quicker. Remember it's usually better to Bond on enemies than allies: they will be slowed and to break it they have to flee, die, stealth and the duration is quite long, Try to put it on someone in themiddle of the teamfight. Remember to shield and boost allies, and try to make it the beam also slow the enemy champions, if they have to back up quickly if they are focused or damaged heavyly.

Thanks for your attention!
Please rate, comment and give feedback if you can!

*Update* 05/02/2011 Fixed some bad wording and spellings, added skill descriptions.