this is my third guide, featuring Sona the Maven of the Strings.
Pls write a comment below. Pls feel free to try this guide.
Gl&Hf.
Rooxe

The Runes are for me always the same
Magic Penetration, for more dmg, even as support
Manareg, for early gaming
magic resist, because of the high AP damage of other heroes, and because of the reason, that AD melee heroes are easier to hold back from you.
and Ability Power per lvl, you should gain some AP, if the money doesnt is enough to buy all AP items

I go with Clairvoyance and Flash.
Clairvoyance: Awesome and best Supporterspell.. NOT CHANGEABLE
Flash is changeable with Ghost but i prefer Flash

and why you shouldnt change it with other Spells:
Exhaust: you are Support not Carry, so.. NOT
Heal:.. ur (W) heals enough at the end, trust me, youll never need it
Revive: useless spell for Summoners till lvl 1
Smite: Nah, let the jungler take this
Teleport: you wont need this skill, u cant def alone and for the rest its useless for support sona
Cleanse: u got heal and flash, enough to get away
Fortify: your not the tank
Clarity: you will normally get blue buff or shouldnt waste your mana, so you wont need it
Ignite: let your teammates take this
Rally:......!

I go Supportsona
R>w>Q>E
you can skill up E as second but in my opinion is a lvl on E with lvl 4 enough done with this skill. It's most time useless.

As Damagesona, you shouldnt play ranked, that will only gain some bad words to you, you only should play damagesona in normal games.
In Ranked play Supportsona is important.
For your Clairvoyance, place it after 10sek behind the enemys nexus.
when its back again you can look at the blue buff for jungler, for possible ganks etc.
You should leave the lasthits for your teammates and heal if you need to heal.
So, you and your lanepartner can stay in lane as long as possible if you dont waste your mana.
Thats IMPORTANT. I'm going to write the importanst sentence with caps because you should think about it the whole game.
NEVER, NEVER WASTE YOUR MANA.
thats all what you need to know. Also, you can last hit minions when your lanepartner is back.

Heal, who needs to be health.
Help, where help is needed.
dont go in melee range.
Use your clairvoyance wisely.
dont waste your Ultimate.
Thats all you need to know

Runes:
Magic Penetration(RED)
Manareg(YELLOW)
Magic resist per Lvl(BLUE)
Ability Power per lvl (BROWN)

Summoner Spells
I take Flash;Clairvoyance

Possible to replace Flash:
-Ghost

Possible to replace Clairvoyance
-NOTHING

Skill Sequence:
I prefer R>W>Q>E
u can also R>W>E>Q, but the first is better

Ranked Play:
Supportsona:
-Clairvoyance after 10sek behind enemys Nexus.
-then to blue buff for jungler, then look for possible ganks etc.
-!!!!!!!!!!!!!NEVER, NEVER WASTE YOUR MANA!!!!!!!!!!!!!!!!!!
-heal,where a heal is needed.
-let the lasthits for your lanepartner, except hes back, then you can lasthit.

Teamwork:
Help, where help is needed.
dont waste Ultimate.
dont run in the meleerange.

Pros:
-good heal in lategame.
-good Supporter
-Megastun
-good early lanepartner

Cons:
-Squishy
-normally, first focus.
-early game against guys like Xin Zhao, hard