Play safe, do not play too risky, because till lvl 6 Singed is easy to kill and to gank. Put your Q to farm more than 2 minions and deal dot to enemys. Throw them into your poison. Boots are very important to escape from a gank or throw back your enemys into your poison. "Catalyst" is important to get a quick heal and quite bit mana per level. Till lvl 4 you can throw back your enemys press Q and slow them with your W.

You have to buy wards. Without wards you get often ganked, so place 1 every 3 min till the first kill/assist. Rod of ages and Rylais will help you with the ability power and health. Rod of ages will help you stay our long time on your lane. Till lvl 6 you have to gank mid or bot, mid with your ultimate and bot with your teleport (teleport to an allied ward). Glacial Shroud will help you get tanky (mana ===> health, armor) so you can tank a teamfight with your ultimate (r) activated. Negatron Cloak will help you get less dmg from magic dmg.

U are OP!