As AD Blitzcrank your 'e' spell is your biggest friend. He deals your whole AD x2 as damage and throws the hit enemy in the air. This deals tons of damage especially in earlygame. you should NEVER start a fight in earlygame without your 'e' ready. His 'q', the grab, is very usefull, too. especially if you have a mate on the lane and it deals quite more damage if you skill it main.

Your first item should be an AD item which gives your 'e' even more damage. B.F sword (if you earned enough money) or Pickaxe are perfect, so try to go back if you have money for one of them. But NEVER forget the boots, cause the most enemies are running away from you cause your damage surprise them, so you have to be fast enough to keep up and finish them. You need the item MANAMUNE very early, so try to biy it right after your boots and your first AD item. As earlier you buy it, as earlier Blitz' shield will increase like his AD...

Your mighty 'e' spell has very less mana costs and is pretty good for farming and lasthitting. AD Blitzcrank deals quite more damage as some of you expect, that's why he is a good lasthitter. Farming is a big point, cause AD Blitz needs tons of money ^^

As summoner spells i prefer ignite for true damage and incresing your AD a little bit, and Flash to get fast out of fights with low life or to keep up to an escaping enemy while my 'e' is activated

AD Blitzcrank deals tons of damage but is very slow in the beginning of the game. But later on he will be one of the fastest champions.