Hey guys, i love sona she is beautiful and awesome and i decide to make this one.
It is my first build and guide, and i believe that you will enjoy it ;-).
You are maybe asking why i named this build Sona's penta kill :D because it looks awesome :D or not ? i am kidding, i believe you can do penta kill with sona, now lets go and test it ;-)
Dont forget League of Legends is a team game, if your team suck, you will suck :(

At the firt Sona is awesome support, but she can be awesome DMG, and u asked me why ? She has a great potentional with her Himn of valor, its huge DMG for 2 closer targets and her ultimate Crescendo, for example its very effective with ash's ultimate. its AoE DMG and AoE stun, its great combo in gangs ;-)

Pros:

+ effective healing - u can heal 2 allies
+ great speed - Song of Celerity , u are very fast
+ escape mechanism - Crescendo, Flash, Ghost and Song of Celerity
+ many auras - great support
+ AoE stun
+ awesome fun if you have brain :D

Cons:

- her dmg in late game, but its discutable
- squishy

Why i decide to pick flash and ghost? its so easy to run away from your enemy with this spells, its the best option for your survival
Flash - great spell if u wanna keep your distance from enemies, or u can combinate with your ultimate Crescendo, you can flash to the best position in gangs and then u can use your ultimate to kill your enemy
Ghost - great combo with Song of Celerity, run forest run, ehm i mean run Sona run :D

then u can pick:
exhaust - its good for every one, you can slow your enemy and its important in gangs
teleport - with this spell you can teleport over the entire map on allies mobs, towers, wards and temmos mushrooms
clairvoyance - is usefull for map checking
clarity - i see it in lot of builds but i think is useless if u have masteris for mana regen and some mana items like Tear of the Goddess or Sheen :)
its your choice what u will pick

Power Chord - After casting 3 spells, Sona's next attack deals extra 24 (+12 per level) magic damage.
Additionally, Sona's Auras persist for 3 seconds after deactivating and set off a 2 second global cooldown. Awesome DMG, you can nuke your ememies or last hit creeps.
This skill is nice in combo with Lich Bane really huge DMG, just great passine i realy like it
Hymn of Valor - your main DMG spell, nice combo with Power Chord and Lich Bane. Just spam this skill and collect kills.
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 60/110/160/210/260 (+0.5) magic damage to the nearest two enemies (prioritizes champions).

Aria of Perseverance - you can heal yourself 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 30/55/80/105/130 (+0.5).

Song of Celerity - you can increased you and your teammates movement 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.

Crescendo - your ultimate AoE stun, its awesome, u can stun all of your enemy and u can run away
Sona plays her ultimate chord, forcing enemy champions in a line in front of her to dance, taking 150/250/350 (+0.7) magic damage over 1.5 seconds.

Maxing:

Max Hymn of Valor and one point at Aria of Perseverance and Song of Celerity, or if you are having hard time with your opponents, give Aria of Perseverance additional point. On 6,11,16 lvl pick ultimete Crescendo

9/0/21 masteries for magician

Offense

9 - improve ap, CDR, Armor pen

Defense

0 - there is nothing for you

Utility

21- improve ghost, mana regen, experience, movement speed, flash and CDR

ehm runes, i pick runes for caster - mPen, mana regen per lvl and CDR, you can also take full AP runes, or some magic resistance runes.
I prefer these three:

Greater Mark of Insight - 8,55 magPen for reduce enemy magic resist
Greater Seal of Clarity -10,53 mana regen,you are magician, mana regen is important !!
Greater Glyph of Focus - 5,9 CDR - for better spamming auras
Greater Quintessence of Insight - 5,3 mag pen
Greater Quintessence of Fortitude it is nice to have an extra additional HP

You can take so many items, its hard to say what its the best, here are AP, HP, mana, resist items. Yes lets start with early items
Early and core items:
Sorcerer's Shoes - mPen its vepy important, ou can also take Ionian Boots of Lucidity, but i prerefer mPen
Tear of the Goddess - mana, mana more mana please :DDD, with spamming your spells i will get 1000mana
Lich Bane - this is your main dmg item, you can combinate with your Power Chordpassive and with your Hymn of Valor, its so much dmg deal, u will threaten your enemies with spamming your spells, and they will run :D
Mejai's Soulstealer - hmm this is very interesting item, but i NOT recommended it because ure very squishy and you have to keep distance from your enemies. And when u have a lot of stacks enemy team will focus you. Its on you :-)
Mid late items
Rabadon's Deathcap - rush this item and get 155 AP and increased your ability power by 30%
Rylai's Crystal Scepter - yeah HP and AP item, its good you will boost you HP and dmg, also will cause slowed movement speed of your enemiesfor 15%(multi targer spells) and 35% for one target spells.
Archangel's Staff - you can improve Tear of the Goddess and get more AP

Other items... now it depend on you and your team what you will build next i prefer Banshee's Veil
Banshee's Veil - its usefull, block 1 negative efect ;-) and more hp is quite helpfull, it dependf on situation
Void Staff - 40% mPen yeah :D
Abyssal Scepter - you can lowers resist of your enemies 20%

Mejai's Soulstealer - hmm its nice to have 20 stacks and 160 AP and 15% CDR, but i dont recommended this item, because ure bigger goal, and other team will gang you, or in team fights you will be focused. It depends on you ;-)
Spirit Visage - dont buy this **** :D

My second game 6/0/6

My first time playing of sona ;-), and i wasn't following my build, but nice score 13/5/36
gothic sona

This is the end, and i hope ure enjoy it. Comment, criticize and like this guide ;-)