You want Blade of the ruined kind so your passive keeps you atk speed high. It helps deal more damge and keep squishy Ez alive. Tri force is great on him for the spellblade and its many benefits and Last whisper to take down the pesky allies who rush that armor early.

When your in lane the bigger point of ezreal is: Poke. Everything in life is a poke war since he is all skillshots. Open with Q. You see in my guild i max it first, because it deals such a high percentage of AD and it your main damaging tool. Then use W and teleport in with E for an addition poke. Lastly if you need to ult. Thats the quick and easy way to play ezreal. Remember with every spell cast your attack speed increases.