Those are basically the three items you need and you may get any other AP or mana, mana regen items. Boots of swiftness if you are slow or Ionian Boots of Lucidity.You may also want to start with a sapphire crystal for more mana. You can also start putting wards down since it will take longer to get the Deathcap.

This is one of my first builds I use Sona a lot I hope you can in any way help me that would be very helpful I use Sona most of the time and a simple build you can fix it if you want it just what ever you would like. I was using Sona for the first time and liked her I hope you do too because she is a wonderful fun char and if you don't think so well... Okay then but at least give her a chance!

Well you replace most items with my build and etc. but most important if you want to support most get one or two AP items and +5 gold items or whatever and start buying wards first put a lot on your side if losing and other side for winning at beginning game put them around in the jungle.