Can /vp/ help me with IV's?

I'm not getting how to do this. I want a Awesome Weavil cause its my Favorite Pokemon and to get that I need a awesome sneasl.

I get Ev training and I get natures but how much of a boost does IV's do?

What does "likes to take siestas mean"?

How do I figure out Good IV's from Bad ones?

Can I just make a awesome Ditto Whore?