I'd like to start this guide off with a disclaimer: I do NOT advise doing this in ranked; while it is strong, it's not strong enough for ranked play and you will loose more unless you're a master of Sona. This guide is intended for NORMALS only.
Also, I'd like to state i'm new the BBCode, so it's not the prettiest guide! I will be working on that as I go though.

Pros

• Pretty massive burst
• Lot's of utility
• Strong laning
• Scales well

Cons

• Could get flamed at by teammates
• Very item dependent
• Early game mana wh*re
• Extremely weak to CC

In a solo lane, Sona can be a monster, or an easy win; dependent on how you play your cards. Below, you will learn my mechanics for the middle lane sona!

---

Early Laning

---

In lane, you should be playing very passive up until level two, poke occasionally and try to freeze your lane. At level two take Aria of Perseverance for extra sustain, and more importantly: To charge your passive, Power Chord. Upon reaching level three, you should have Song of Celerity, and with some mana management you can start poking.
The combo I typically use is: Heal with Aria of Perseverance to get 1 stack on Power Chord, then use Song of Celerity to speed myself up, and to get 2 stacks on my Power Chord and finally, use Hymn of Valor followed by Power Chord to do pretty insane burst damage.

---

Early Item Explanation

---

The most vital item you're going to want to get is Sheen. It will give you the damage you NEED early on. After your Sheen, go for a Needlessly Large Rod followed by Lich Bane.

Explanation

---

In the mid game Sona has a lot of roaming and ganking potential with Crescendo. Upon shoving middle lane, and forcing your opponent back, you should probably try to gank bottom with your jungler.
If you find yourself in a mid game teamfight, you're not going to be as durable as you want to be, so try to avoid all in's until you have SOME durability.

---

Mid game items.

---

At this point, you should have Lich Bane and Rabadon's Deathcap; and now you need some durability! This is the point where you'll want to build a Rylai's Crystal Scepter. It gives Sona an almost perma-slow on her Q and gives 500hp for that extra durability. After these items, you should probably go for a Zhonya's Hourglass or a Deathfire Grasp depending on which active you need the most.

Now that you've finished up your build, and your doing tons of damage, you should be either fed or it's very late game.

---

Late teamfights

---

Your role in late game team fights is to burst down high priority targets such as: Assassins, ADCs, or squishy DPS mages. Try to maintain good positioning, and not getting caught out as you're a large part of your teams damage.
If you must, try to initiate a fight with Crescendo, if that's not needed wait for another high CC ultimate such as Leona's Solar Flare or Amumu's Curse of the Sad Mummy to follow up on that.
Your ultimate can also be saved to catch fleeing targets to make the push to win easier. Just try to make the most use out of your ultimate.

---

Dueling

---

Sona is not much of a duelist, as she focuses more on AoE and multi-target damage instead. While roaming alone, try to keep two stacks on Power Chord at ALL times so you will be ready for a fight.
You should be able to fight squishies very easily. With a full build, i've instabursted an Ezreal with just my Q / Power chord + Lich Bane proc / W / Lich Bane proc.
As Sona you should never attempt to fight any tanks or tanky bruisers as you will most likely loose that fight(Unless you're a God)

---

Build explanation

---

Generally, the core items of this build gives Sona what she needs to stay alive and do damage, and stay alive. As for the situational items, build Guardian Angel when you're dying a lot, or respawn timers are long, Void Staff for when the enemies build a lot of MR, and Abyssal Mask for the MR and mpen. If you're playing in lower elos and the enemies are too stupid to build MR, go for the + + for maximum damage; if the enemies are smart, trade in either Zhonya's Hourglass Or Deathfire Grasp(depending on which active you find more useful.) for a Void staff or Abyssal.

Sona is a surprisingly viable mid laner, who actually works with high CC or disengage team comps. So, give it a shot. You may just fall in love with it as I did. I hope you guys enjoyed my little guide! I'm looking forward to seeing your guy's feedback, and improving as I learn!

5/5/14 - tried to improve the aesthetics a bit. Need some feedaback on that. Added situational items.
6/5/14 Updated the runes and some text.