Everyone Pokemon gives Effort Value Points when you knock it out. You can find a full list of what Effort Value's you gain from what Pokemon. As well as some great places to Effort Value train on Bulbasauria.
http://bulbapedia.bulbagarden.net/wiki/Bulbasaur_(Pokémon)Effort Values allow you to add a handful of statistics to two statistics. Adding further customization to your Pokemon team.
IV's are something completely different. These are added base statistics. Which are given to a Pokemon randomly when you catch the thing. A Pokemon's IV's are the same from the time you catch it. While Effort Value Points have to be acquired by knocking out Pokemon.