Some of the credit goes to my brother, who introduced me to this game. Well, this is my first build, but I love Sona, and I noticed that the other AP Sona builds weren't exactly excellent, so I thought this one would work. To start off, Sona is mostly support, but I like playing her AP as I suppose a ton of people do haha. She can do great burst damage and if you use her passive effectively, she can take down some of the best mages/ high HP characters. Her Ability Power also raises her heal, so she can help even more :D. Anyways don't worry about getting to many kills, because she mostly gets either assists or killsteals the person. She's very good at harassing early game. I know it might be a lot to read, but continue reading to learn more about my choices in items and how to play Sona.

Initially, I think you should get magic penetration runes because even if tanks try to get magic resist to defend themselves from you, you will still do plenty of damage. Then, I suggest getting mana regeneration runes because at lower levels you will still need the manage regeneration from those. During team fights, you will most likely be spamming your keys anyway, so regeneration is nice. Then I suggest that you get Ability Power runes, because more Ability Power= More Damage+ More Healing. If you decide that you don't like my rune choices and could think of better ones, like I said, this is my first build. I could also suggest some cooldown runes, but I would suggest cooldown quintessences.

Of course, like with any caster, you want to get the 9 on offense for the 15% penetration... It will help A LOT. Then I suggest the 3 in regeneration because early game, you need it in order to keep your mana up. Try to get the Blue buff as often as possible to keep your mana really high.

I chose to use Clairvoyance and Flash due to the fact that if you're in trouble, Flash can get you out of it and away from them and then use your "E" skill in order to move faster. You can also use it to flash to somebody and kill them with either your passive or your q skill. I chose to get Clairvoyance because Sona is a VERY SQUISHY character. She needs to know her surroundings at all times. You have to remember to keep a good eye on the map and the things around you. Alternatives could be clarity in case you need the mana at the beginning of the game, but with the runes I suggested, you have a lot of mana regen already.

Initially, I get a Meki Pendant to have increased mana regeneneration since they no longer have Innervating Locket. The reason I suggest the movement speed as opposed to the magic penetration is because you really need to get places and away from people more than you need to penetrate their magic resist. Stacking Archangel's Staffs can be very useful because of all the Mana Regen and Ability Power. The passive on Rabadon's Deathcap is very useful along with the NON UNIQUE PASSIVE on Archangel's.

I chose to get the "Q" skill first because you need the damage. Then I suggest raising your heal and attack at the same time because you're still a support even though you do damage. Also, at the beginning of the game while still on the platform, charge your passive twice or 3 times to activate it. Then go to your lane and try to hit their Champion first.

I suggest you lane with a melee or DPS character because your Ultimate, or "R" skill can stun them while they kill them. Charge your passive with "W", or "Q" against minions. After getting 2 stacks on your passive, hide in the brush and wait for them to get near you. Pop out of the bushes and use Q and then right click to activate your passive on them. This will do a lot of damage at low levels. This is when you try to start getting the blue buff to SPAMZOR.
Tip: You can use your "E" skill to speed up minions.

I suggest you try to keep your turret as long as possible, and if you have decent teammates, they will come help you and "gank" the opposing team. Also, feel free to switch lanes depending on which one needs help. Continue doing what you did Early game, but BE CAREFUL. In team fights I suggest you stay back a little to try not to get focused, but go forward a little to use your Q. Q is good for farming minions all throughout the game.

This is when you have enough mana regeneration and mana to just spam heal, movement speed, and your attack on minions. Try to stay back away from major DPS such as Ashe or Yi. If they try to focus you, stun him with your "R" and then have your teammates focus him down. This will almost always kill them. Try not to ever travel alone. Use Clairvoyance to reveal the buffs around the map or the Baron/Dragon.