good guide.
BUT:

1.
"Catalyst the Protector- Obviously you open with a Sapphire Crystal for the bonus on Singed's passive, but what do you rush after that? CATALYST! Don't invest into ANY other items until you get Catalyst. Don't get shoes, your runes and masteries will take care of you for a bit. If you rush Catalyst, you will hardly ever be OOM. It's unique passive allows you to stay in lane, poison spam all the minions and champion you are laning against, and is overall a BEAST item early game. BUT, don't get too cocky when doing a poison rush. I'll get into more detail with that later."

that later didn't exist. you haven't really elaborated about that.

2.
though its a satisfactory guide, its not that deep; you should've gave details about some things, for example: what to do when facing ranged solo top/or against specifics like vs. gangplank/irelia.
you also should've told what to do and explained how and when to turret dive the opposing champion which singed is kinda good to do(advance, poison the creeps, with correct timing, fling away from the turret. that is ofc if enemy is >30% hp, and enemy jungler is away)

did not voted.

Its a realy good Guide.

Very nice guide keep up the good work! :D

Well, I'd say I disagree with a few things in this guide.

First off, CC is Singed's worst enemy, right? Then buy mercury treads.

Rushing Rod of Ages is always a good idea with Singed

If nobody on your team has a Frozen Heart then you need to get one.

Building Rod of Ages then building Force of Nature will make you invincible.

Try putting Ignite and Ghost instead of Ghost and Flash. This is because you can run up to the enemy, poison them, Fling them, then once they start running to their turret, Ignitethem, it will get you so many kills. Ignite is like a second poison.

Overall though, good work and I know you put a lot of time into this!
+1

Good guide

Awesome dude, keep it up, SINGED ! :D

nice guide, the same build as i use! :) picked up on a few things while reading, keep it up!

nice guide but way too common, try adding something that hasn't been seen before on a singed guide

Absolutely a good guide, +1 ;)

maybe you can read and vote my guide too

+1 from me.
I prefer Merc Treads for the tenacity, but ninja tabi is fine too.
Not really sure Sunfire Aegis is worth it, i much prefer Frozen Heart or Randuin's Omen
Also, you should improve the overall presentation, add some images, dividers, columns etc.
You should go a bit more in-depth too; What about alternative items, runes, masteries, summoner spells etc?
Gonna check back later, good luck.

me gusto me sirve gracias man