I Like Poppy so much that i want to marry her!
I am a big fan of AP chars such Lux, Morgana or karthus, but the favorite char is Poppy especially with her Noxus Poppy Skin!

True is awkward runepage but it works, poppy Q and E skills use bonus magic damage, so i chose this runes based on AP so you can actually start to get fed at beginning!

Start buyin Dorian's Ring or start making boots as you wish, but Dorian's Ring probably the best choice so your abilities can be better in beginning, than you have to buy Madred's, now u have to buy Bilgewater so u can make magic damage using it as skill and finish the hextech gunblade, than u go with bloodthirster to get even more lifesteal, than u make black cleaver, now that's up to you, either u can buy infinity edge to get more damage, or buy frozen mallet(always buy it) to slow down enemy and get more life points!

I use ignite because u can get stronger ignite on your enemy that is under Dipolatic Immunity.

And use ghost combined with your W skill that gives u more speed, maybe ultra speed when combined!

Pros

Great Turret Diver
Great Fight igniter(better than some tanks) cuz of her ulti
If land Q ability against the wall u stun :)
Great Assassin

Cons

Beginning Terrible farmer
Not really outstanding early game

I suggest u use your ulti always when u are about to start the team fights, be u the igniter, or use it when u are ganked by enemies targeting the worse of course!

Try always use Heroic Charge agisnt the wall so ur teamates can gank and atack too especially early game, and u can use that skill to gank other lanes if necessary, if u under tower defending put them against the wall so ur turret help u out!