There are two problems with a massive world-building infodump at the start:
While you're infodumping, you're not, well, telling the story.
You're kind of relying on the read to then remember what you've told them later on.
So, the best way to do it really is to just reveal details as they become relevant (and, for best results, as your characters encounter them).
Also, keep in mind that the reader will know how they should react to something by how your characters react to it, so whenever you can, introduce worldbuilding in such a way that your characters can react in some manner to it.
That's my two cent's worth, anyway.