I'd like to thank all who have commented so far. Both Lestnor and Halipupu provided ALOT of information that was very useful and gave me a lot to consider. Like I said I will slowly be editing this/building new builds as time goes on and greatly appreciate the considerate information you have given to help me with my own game as well as my guides for, hopefully, helping others.

haha nice man i realy like it and find it very effective.

In my opinion you should be getting Tear of the Goddess a lot earlier so it can stack, because it's not all that expensive. You will lack mana regen without mana regen runes and Clarity isn't always ready. Also buying boots first sucks, because you lack mana regen and don't really need the speed boost.
Will of the Ancient can be useful to your team, but you don't need it yourself, it should be one of the items you'll be getting because you have only one attack spell anyway and you have a heal so that's why spell vamp is not all that usefull.

About runes, I don't see the reason why you should pick defensive runes and defensive masteries to Sona, especially since you mentioned it would be good for mid. As a supporter on side lane with an ally it would work, but you still lack some AP with this item build.
Also you mentioned you don't get aura items, but most of those ARE aura items, therefore good for your team but ONLY if your team has a bunch of casters.

Expanded Mind mastery scales of your base mana is therefore pretty much useless, you should pick prolly AP per level mastery or HP regen mastery.

Alltogether your item choices might help the team, but are quite expensive and as someone already mentioned you won't be getting AP enough early so the game might be over before you even have a good heal. I nrecommend building up that Archangel before completing Will of the Ancients, also buying that Tear of the Goddess BEFORE completing tier 2 shoes so that it can stack and you won't have mana problems.

Sorry, I've gotta downvote this, for several reasons.

Your masteries:
-Yeah, it never hurts to have 6 more armor and mRes, but it's a small increase and there's better things to put those points into... more on that later...
-Greed is bad, I'll just leave it at that. Over the course of an entire average-length game (about 40 minutes), you'll gain 240 gold. Total. It might seem like a nice mastery at first glance, but it's just not worth it.
-Expanded Mind is also pretty minimal. You don't build any mana items until mid-late game to capitalize on it, anyway, but let's say at the end of the game you're level 18 (1120 mana), and have built your Archangel's Staff, and have 500 of the 1000 bonus mana (which is generous; you don't build those stacks very quickly, and you have the item much later in your build than most Sona guides). That's another 900 mana from the Archangel's staff, which brings you up to 2020 total. A bonus 5% is 101 mana. That's not even enough for two spellcasts, and that's assuming you even get that far. And you spent four mastery points on this! Totally not worth it.
-Perseverence is bad. This forum thread explains it better than I can, so: http://www.leagueoflegends.com/board/showthread.php?t=219077
-On to what you could be getting instead of all that: a full 10% cooldown reduction, 15% spell penetration, 10 more AP at level 18, and 30% extended neutral buff duration. About the buff duration, since it might seem like a little odd of a choice: Blue is amazing on Sona; the mana regen lets you spam your spells and keep your allies topped out on health, and the CDR lets you cast faster, which means more heals, damage, and power chords. You'll also occasionally be getting neutral buffs on those rare occasions you get a kill on someone who has one. Increased buff duration isn't near as essential as the other stuff in the Support and Offense skill trees, but it's still usually stronger than the other alternatives.

Summoner Spells:
There's no section for these anywhere in your guide! Summoner Spells are based largely on personal preference, but you should outline the viable and not-so-viable ones to help people chose. I personally run Flash/Clairvoyance, because you already have a movespeed increase, a slow, and if things get really hairy, your ult can be used in a pinch to get away from pursuers.... as long as you first get out of their range to stun/snare/slow you in the first place. Flash helps a lot with that, and I find I don't need Clarity as long as I'm careful early game with my skills. That's just my two cents though, there's no definitive best summoner spell combo for Sona; the main point is that you should go over them somewhere in your guide.

Skill order:
In my opinion, you REALLY don't need Song of Celerity at level 3. Going Q/W/Q/W/E or Q/W/W/Q/E seems a much better choice to me, especially since the effect of your heal doubles from level 1 to level 2, and it's only at level 2 that it becomes effective.

Item build:
Why do you get boots first? It doesn't give you any of the things you need on Sona starting out: ability to stay in lane longer (meki pendant or mana crystal), survivability (doran's ring), or a little bit of AP for extra damage/healing (also Doran's ring). Also, there's absolutely no need to rush your level 2 boots so early, especially without first getting something else. Going from Boots of Speed to Merc Treads costs 850 gold (most expensive boots in the game), and just gives you slightly faster movespeed, a little bit of mRes, and the decreased CC duration isn't useful in the laning phase. Once you get into a few teamfights, they're damn good boots, but it's not worth it to rush them and sacrifice a good early game for it.
Hmm, Soul Shroud, and then Will of the Ancients... I have a feeling you're going for lots of auras to support your team here? That's all very well and good, but Will of the Ancients is your first major AP item, and it's only 70 AP. You're going to be really ineffective up until you build your Archangel's, and by that point the game is probably mostly over since Sona is support, doesn't farm well, and shouldn't be getting a lot of kills. In addition, the spell vamp aura is only really great if your team has a lot of casters, so it's a very situational item. When you're doing well, Mejai's can be a decently good AP item on Sona simply because if you're playing her right, you should be dying rarely if ever, and you get a lot of assists. If you're looking for a little bit of survivability, too, I'm a big fan of Spirit Visage to fill that niche instead of Soul Shroud, because it's a lot cheaper, still gives CDR and health, as well as some mRes and buffing your heals on yourself. I'll just leave it at those item suggestions, though.

Hopefully this helps. I'd like to be able to change my vote to a +1 eventually. :)

Not a huge fan of the item build. It's very expensive and it's not gonna be easy to complete as a support. Also, if you play Sona as a carry � this builds lacks other vital stats.

On a side not, your masteries are messed up!

Love this build =)

Some spelling errors but GJ overall.