I've been playing this game for about 2 years now and have climbed from gold V to Platinum I in one season with playing only singed. Enjoy the guide!

Pros: Very strong when you get ahead
Can put so much pressure with proxying and stealing jungle camps
Very good at splitting because escaping is easy
Even when behind can be extremely annoying for the enemy team
Strong gank setups
Strong mid game
Strong teamfight

Cons: Hard to cs in certain matchups
Can be pushed back into tower not allowed to cs and not able to back
If behind against certain matchups cannot move out of tower
Easily hard countered
Weak late game

The entire premise I use to play singed is always push in lane and look for a proxy into a roam or a just flat out roam or tp gank. If you push the wave in extremely fast then proxy a wave down you get a free rotation into mid or a back and tp gank onto bot. You WILL NOT CLIMB RANK if you do not have extreme map presence. Going even or winning lane is nothing unless your entire team is doing fine and winning their lanes. Help your team especially bot lane because singed thrives when fighting multiple enemies.

Always push in lane to set up a proxy unless all lanes are un-gank-able or if their jungle has a lot of cc and/or is fed and will have no problem ending you. If you can clearly see they are far bot lane and low or something go for the proxy anyway but generally they come faster than you might think. When a kill or just very ahead in cs of your enemy laner you can attempt to proxy fast then take the enemy's jungle camps. Do this in-between waves and usually if you have vision of their mid laner. If you are very strong sometimes the mid laner will come and you will kill them as well as possibly their top with your extreme cs and xp advantage and usually your midlaner's help which will come a bit later.