Try this page, it will tell you about horde training and the different items that will help with your EV training. Hope it helps, but there is kind of a lot to it I don't really want to try to explain it all here.
Head to Route 119 or 120, and get a tropius. They have sweet scent and will help you with attracting hordes. With the EV items, EXP share and a pokemon with surf (to defeat hordes), it shouldn't take long to max out an EV.