Hello and Welcome to my Sona guide.I'm german so I excuse myself because of some grammar or vocable mistakes.I hope you enjoi reading this guide anyways.I hope you leave a comment and i'd like to have some responses.I am open to critisism.

4.26.11 added pros/cons

Runes:

My Recommended

Marks: Greater Mark of Magic Penetration for some significant damage at the first few levels
Seals: Greater Seal of Ability Power adds some heal and damage before you get your AP items.
Glyphs: Greater Glyph of Scaling Cooldown Reduction with these Runes and the Items you come to 40% CDR hardcap
Quintessences: Greater Quintessence of Ability Power same as Seals

Also Possible

Marks:
Greater Mark of Ability Power
Greater Mark of Replenishment
Greater Mark of Armor
Greater Mark of Magic Resist

Seals:
Greater Seal of Scaling Mana Regeneration
Greater Seal of Scaling Ability Power
Greater Seal of Evasion
Greater Seal of Armor
Greater Seal of Magic Resist

Glyphs:
Greater Glyph of Ability Power
Greater Glyph of Scaling Mana Regeneration

Quintesdsences:
Greater Quintessence of Scaling Mana Regeneration
Greater Quintessence of Replenishment
Greater Quintessence of Scaling Ability Power
Greater Quintessence of Movement Speed (If u don't like Boots of Swiftness but want to be faster)

Masteries:
I got the standart Utility Masteries with improved Teleport and Flash.
Also 3 points in Perseverance for more Heal at yourself, 4 Points in Awareness to level up faster, 2 in Expandet Mind to get more Mana, 3 in Meditation for Mana regen, the next three Points went into Quickness getting the improved movementspeed,Intellegence because of the CDR and Presence of the Master to get the CDR on your Summoner spells.I put the remaining points into the Defense tree gettin 3 points in Hardiness,Resistence and Strength of Spirit to get some survivability.

Skills:

Power Chord : After casting 3 spells, Sona's next attack deals 14 + 9 x lvl bonus magic damage in addition to a bonus effect depending on what song Sona is currently pl aying.

Additionally, Sona's Auras persist for 2 seconds after deactivating and set off a 2 second global cooldown.

Use the blue to last hit minions or deal damage to squishy targets.
Use the green to hit the enemies stronges Carry or if he isn't in range their most damage dealing meele champion.
Use the purple to slow the most valuable target if they run away.

Hymn of Valor : Sona plays the Hymn of Valor, granting nearby allied champions bonus Damage and Ability Power. Additionally, casting this ability sends out bolts of sound, dealing magic damage to the nearest two enemy champions or monsters.
Persistent Aura: Sona plays the Hymn of Valor, increasing nearby allied champions Damage and Ability Power by 6/8/10/12/14.

Activation: Sona fires bolts of sound, dealing 50/100/150/200/250 (+0.7) magic damage to the nearest two enemies (prioritizes champions).

Power Chord - Staccato: Deals double power chord damage.

Cost
65/65/65/65/65 Mana
Range
700

I use this Ability to harass the enemy Team in Teamfights and on the laning phase.Try to not steal kills with Hymn of Valor.You also can farm minions with this skill but you have to learn how to.

Aria of Perservance : Sona plays the Aria of Perseverance, granting nearby allied champions bonus Armor and Magic Resist. Additionally, casting this ability sends out healing melodies, healing Sona and a nearby wounded ally.
Persistent Aura: Sona plays the Aria of Perseverance, increasing nearby allied champions Armor and Magic Resist by 8/11/14/17/20.

Activation: Sona sends out healing melodies, healing Sona and the most wounded nearby allied champion by 35/70/105/140/175 (+0.35)

Power Chord - Diminuendo: Reduces the target's total damage output by 20% for 4 seconds.

Cost
65/65/65/65/65 Mana
Range
1000

Use Aria of Perservance to always heal your allys even if they just got some Hp left.Spam it in Team fights and on your lane after you got the Tear of Goddess

Song of Celerity : Sona plays the Song of Celerity, granting nearby allied champions bonus Movement Speed. Additionally, casting this ability energizes nearby allies with a burst of speed.
Persistent Aura: Sona plays the Song of Celerity, granting nearby allied champions 8/11/14/17/20 bonus Movement Speed.

Activation: Sona energizes nearby allies, granting them 6/8/10/12/14% Movement Speed for 1.5 seconds.

Power Chord - Tempo: Slows the target by 40% for 2 seconds.

Cost
65/65/65/65/65 Mana
Range
1000

Song of Celerity is often underestimated.Always spam it if your Team is on the hunt or gets hunted.Always use it before a Team fight or in a Team fight because it hits all your allies and will give you stacks.Also the Power Chord effect is great and i try to use it as much as i can.

Crescendo : Sona plays her ultimate chord, forcing enemy champions to dance, taking magic damage over time.
Sona plays her ultimate chord, forcing enemy champions in a line in front of her to dance, taking 150/250/350 (+0.8) magic damage over 1.5 seconds.

Cost
100/150/200 Mana
Range
1000

Use it always in Teamfights and try to hit as many Targets as possible.Don't be shy to use it on single targets,if your team can get a kill or it saves a teammate it is worth it.


If the games goes good and u dont get harrased much:
Levels 1-6
Hymn of Valor >>> Aria of Perseverance >>> Hymn of Valor >>> Song of Celerity >>> Hymn of Valor >>> Crescendo

Levels 7-11
Aria of Perseverance >>> Hymn of Valor >>> Hymn of Valor >>> Aria of Perseverance >>> Crescendo

Levels 12-18

Aria of Perseverance >>> Aria of Perseverance >>> Song of Celerity >>> Song of Celerity >>> Crescendo >>> Song of Celerity >>> Song of Celerity

If you get harrased much :

Levels 1-6

Hymn of Valor >>> Aria of Perseverance >>> Aria of Perseverance >>> Song of Celerity >>> Aria of Perseverance >>> Crescendo

Levels 7-11

Hymn of Valor >>> Aria of Perseverance >>> Aria of Perseverance >>> Hymn of Valor >>> Crescendo

Levels 12-18

Hymn of Valor >>> Hymn of Valor >>> Song of Celerity >>> Song of Celerity >>> Crescendo >>> Song of Celerity >>> Song of Celerity

My Recommended

Teleport : TP is very helpful to get to your Teammates which need help.If you see your Mates fighting and a ward or a Minons is nearby use your port to get there and help your Team. Also you are not that good ar Farming so if u see a huge minion wave near a friendly Turret go to defend it and farm some more gold.

Flash : You are Squishy,and you will be focues very often.Thats why i get Flash to get out of dangerous situations or to position myself in Teamfighs to land the Crescendo.

Also Usefull
Clairvoyance :Good to scout bushes of detect the position of the enemy Team.You don't have to facecheck bushes.

Clarity :IF u like Spamming your skill from early on its nice to have but with the build in the endgame useless.

Cleanse : Possible because of the CC remove.

Ghost : As a replacement for Flash,depending on the playstyle.

Useless Summoner Spalls:

Exhaust : You shouldn't get in Exhaust-Range, and it more useful on meele Champions.

Fortify : Well you could protect a Turret but it has a long CD and isn't that useful,let your Tank take this spell.

Heal : You have a Heal ability and its not that useful in lategame.

Ignite : Same thing as Exhaust

Rally : This spell is a pure Turret-Push spell and should be taken by Champs like Master Yi or Twisted Fate

Revive : Well the 9 or 10 mins CD and Sona as a bad Champ to defend or push makes this spell useless for you.

Smite : I think i don't have to explain this one.

Early Game:


Start Items:
Meki Pendant: It will give u the mana regen you need in the first few levels.
2x Health Potion: Hold your helth up without havin to spam your heal ability.

Early Game Core items:
Tear of Goddess: Now you can spam your spell and get the mana u need.
Boots are situational:
Normally i get the Boots of Swiftness because you are really slow.
If your enemy Team got lots of CC get the Mercury's Treads, well they explain theirselfes.
Against a heavy DPS team get Ninja Tabi if you are on the focus for some armor and dodge chance and Boots of Swiftness if not.
Kinglegem also is a core item in the eary game to get some Survivability and CDR.
Amplifying Tome to get some AP.
Mid Game.
When the ganks and team fights begin you should get Mejai's Soulstealer to get some AP again.
Finish off the Soul Shroud and the Archangels Staff.
Now you should have enough Mana,AP and HP to survive a Team fight and let your teammates survive too.

Late Game:
The fifth Item is situational again.
Against a mixed Team get Guardian Angel,so noone will focus you again.
If the enemy Team is Caster-Heavy get a Banshee's Veil.
And get Randuin's Omen against a heavy DPS team

I start with Hymn of Valor and cast it two times in the base.If your enemies show up first try to hit them with the Hymn and the Power Chord.Most Champions lose half of their HP or more if they get hit by this combi.

Try to farm as many last hits as possible,wich isn't that easy because Sona's standart attacks don't deal much damage.After you get Tear of Goddess spam your Aria of Persercance and Hymn of Valor to hold up the HP of you and your laning partner and push back the enemy minions.Try to learn how to last hit with Hymn of Valor,because if you are good you will always get two minion last hits with the one spell.

Your positioning is everything in Teamfights.

Aggressive positioning:

Try to stand between your range carrys and your meele dps and tanks.Spam your Aria of Perservance and Song of Celerity to get as many assists as possible.Use your Hymn of Valor just if all the other spells are on CD.Always try to hit their range carries so they can't deal damage anymore.

Defensive positioning:

Stand next to your range carries and cast Hymn of Valor to increase their damage output.If you see one of your meele allies running out pf HP go to him and cast Aria of Perservance and heal him up.Also try to hit all their Champs.

Hidden positioning:

Hide in a brush when the teamfight starts and if the enemies get to aggressive cast Crescendo in the middle of them.

I recommend the first way of positioning.

I will add some of my stats soon.

Some i tried,will add some other too if they work.

Mordekaiser
Xin Zhao
Pantheon
Irelia
Trundle
Renekton
Cho'Gath

Pros:
-Heal
-Aura-War
-Multiple Target stun
-significant damage early game
-can be a gamebreaker
-is viable in Ranked games too

Cons:
-squishy
-often focused
-dead if chaught(exept Flash is up)

If you follow the guide you will be a great advantage for your team and they will be happy to have you on their side.And always remember you are a Support and not an AP-Carry.

Have fun playing Sona and let her play her Masterpiece.