Hey Guys =D this is my first guide + im a very lazy person so i will just show you my core build and sum the rest up for you.

Singed is imo one of the top 5 solo-lane chars in the game.
Running in front of the enemy minion trail with Poison Trail makes early game last-hitting easy.
If played on duo you can play so agressive it should be forbidden. As soon as you grab Tear Of Godess you have infinite mana flow, so that you can leave your Q on at any time.
Singed is awesome for ganking, because you can build up to almost 520 movement speed by combining your Ult with Ghost at lvl 6+. Use your E to start teamfights and isolate carries from their teams by comboing your E and then W their way back. Make sure to always stay in front of your enemies, as Poison Trail is your Damage Output. I will collect some clips over to next days and i will link a video under this summary where is show how to use his spells to his full advantage.

Ps: You can play pretty much any other summoner spell instead of Reinforce, but it's just hilarious to grab kills with it and troll those cocky ad carries thinking they can single turrets =D