I think you could/should build in more situational items.
I'm not sure if you should really take the penetration runes. Sona is really damn squishy and basicly you really need all the armor you can get. If i play an agressive sona, i take Ap Quints instead of gp10s. It is risky, but if you are premade with your adc, or if you are sure that you can "carry" your adc and you plan to outpoke your enemy, I think AP Quinss are actually an option. Depends on your playstyle.

Hey Kooba!
Sona is a very in depth kind of support that cant be summed up so quickly. She has a basic role and is easy to learn but extremely hard to master for competitive play and I feel like you are missing many key points as well as viable item options for her. I won't downvote but seriously needs some work on BBCode and expanding on the basics that you currently have down. HMU if you want more of my input as I am quite the avid Sona support player and am also quite good with BBcode.

Why would I put in effort on constructive criticism for an author who doesn't put in effort?

^ You could at least give your reasons as to why it is a "**** guide", as you put it. Just saying "**** guide -1" comes off as really rude and childish. But yeah, Ravenholm and Greenfrogs said it all already, and I strongly agree with them both.

**** guide -1

Runes are wrong. Masteries are wrong. By the way, if you actually knew how to support, traditional supports can carry their lane pretty damn hard. Early game they do just as much if not more damage than the adc, they have the utility, they make the plays. Their role is to get their adc fed then build aura items because they get no gold. They give vision which is worth more than item in the game. If you're a good support you're going to be doing more carrying for the first 20 minutes of the game than your ADC.

Walls of text pretty short and i think could be more informational

[-1]
If there was a guide writing elo, let's just say you would need a guide like this. (I'm implying that this guide is terrible if I didn't convey my point properly.) Never make another for the sake of humanity. Or just read the guide to making a guide by JhoiJhoi and improve this one.

Sona isn't a low elo support. You see her in Diamond all the time.

Also you went 21 points into Utility without taking the 3% MS mastery. That's not good.

ok, first off, I'm going to assume C2V is off. turn this on to avoid random downvotes in the future. however, you'd probably going to get a lot of downvotes anyway.

your guide is one huge wall of text. I am not going to read thru it, nor vote on it due to lack of presentation. check out jhoijhoi's how to make a guide guide (just mouse over the "Builds & Guides" menu and you'll see a link to it near the bottom. it's that important!) before you/if you decide to edit your guide.

in a nutshell your problems are:
no bbcoding
no pictures
walls of text
it's short
no situation items
lack of idea flow

your only saving grace is your cheatsheet isn't improperly filled out leading me to believe you do know what you're talking about, only lacking the proper means to present it. thus, go check out the how to make a guide guide.

well that's that, I ripped you to shreds then ripped those to pieces. sorry. there will be others that will come along and do the same thing and probably be a lot less helpful. it does get annoying to see the same thing over and over i suppose.