Under Lucario's Rule!

Breeders have known of EV training for a while but its quite newer for the pokemon trainers.First of all EV means Effort Value, and this helps in raising a pokemon in a certain stat. EV training can be confusing at first but it does get easier as you go on and grow on using it.

Tip #1: Getting the EV items from the Battle Tower prize house isn't neccesary but it does help a lot. Each item costs 16 bp (Battle Points)
*Power Anklet- Speed
*Power Bracer- Attack
*Power Band- Special Defense
*Power Belt- Defense
*Power Lens- Special Attack
*Power Weight- HP

Alright, now the next thing that you need to know if what pokemon give what kind of boost in EV training. This may confuse you as well because of the evolution process intwangling in with the EV process. You see, a Magikarp gives on point in EV for speed when Gyarados gives 2 EV points for Attack. Since there are a lot of pokemon I'm not gonna list what EV every pokemon gives.

Tip #2: Until the pokemon that ur EV training levels up, then your gonna want to stick to the same pokemon that you've been battling for the max amount of EV points that you've earned for that battle.

Tip #3: A great place to go for EV training advice is Serebii.net where you can look up a pokemon in their D/P pokedex and see what their max stats can be or what they give for EV points.

See, this guide to EV Training is short and great... That's why it's called EV Training Guide for Dummies! Hope it helps!
(by leveling up 2 times fighting only Magikarp along the bridge from the Eterna Forest to the City, my shiny Jolteon got 35 evs in speed!