Dinger is an APC champion, i will tell you how you can build dinger correctly and dominate your land.

a side note: this is my first guide

for runes i go with cooldown reduction, mana regen, magic penetration, and AP. Dinger is very mana hungry and need mana regen. he also can do massive damage to enemies as he does magic damage and most champions don't have a lot of magic resist. the more magic penetration you have the more damage you can deal. cooldown reduction will help you to get your rockets faster so you can give the final blow on any champion trying to escape.

i went 20/0/10. in offensive i go with cooldown reduction, magic penetration, AP, and some random stuff i isnt really unnecessary so you can put 4 extra points into anything you want i just went with those so i can get to tier 4 to get the AP. in utilities i go with increases movement speed, mana regen, increased mana, summoner's insight, and summoners spells cooldown as it will help you to get flash fast to escape battles.

i mainly go with the offensive build, but it is recommended to build into defensive as hourglass is needed for late game when you get into battles. you will be receiving heavy damage and will die in 2-3 hits if your not to careful, but if you stay back from battles then building into my offense is a good build to finish off or weaken any champion.

q,w,q,q,e,r,w,w,w,q,r,w,q,e,e,r,e,e

q is what i always pick first as it will help you to collect gold even when your not in your lane. it also help to push your lane. once lv 4 i bring my q to level 3 as it allows you to build 2 turrets and maxing it out a lv 13.
w is your harassing ability in early game using your w often will push your lane quickly as it allows to fire 3 rockets, but be aware your rockets will fire minions as it first priority so when you see more than 3 minions don't use your w. i max this at lv 12
i rarely use my e as it only helps to escape from battles or kill a large amount of minions as it takes a long time to land on its target and can end up being a waste, but using your r will increase the speed of your grenade. i max this a lv 18
r is a skill you want to get as soon as its available. lv 6, 11, and 16 as its passively reduces the cool down reduction. when active it heals your turrets and allows them to slow their targets and also allows you to fire 5 rockets.

flash and heal will help you to escape battles or anyone ganking and survive longer. you can always replace these spells with:
teleport- dinger is slow and this will help him get to his lane faster.
exhaust- slow enemies down so you can get the final kill on them.
ignite- kill anyone that low on health to finish the job

Pros:
-good lane pusher
-high magic damage output
-great harasser
-can defend good
-can solo dragon
-can solo lanes
Cons:
-very squishy
-very mana hungry early game
-your dead when ganked
-slow movement speed

Dinger isn't a jungler even with his turrets. however once at level 11 or 12 he can solo the dragon. place both turrets in range of the dragon and start using your skills. don't use your ult unless you need to.

a great way to work with your team is when an ally is escaping a fight have him go into the jungle and set up your turrets in a bush and use your ult. when they get in range or your ally go into the bush and once the enemy goes into the bush use your e and start spamming your w.
a great lane partner is blitz. you can place your turrets around him and use your e when he grapples on a champion and will easily die.

w and q are dinger's main skills that i use doing massive damage to anyone and everyone.

q are your main source of farming ex and gold. placing 2 turrests in to different lanes will provide you maximum gold, but they can move and have to be replaced.

this build and strategy has won me every game that i have use dinger. i haven't lost any game with him so far. so if you play your cards right you can bring your team to victory.