Writers love words, but sometimes, words don't like writers. Especially when it comes to info dumps.
What is an info dump? Well, it is when you drop a load of information onto the reader. They are boring chunks that are generally found in dialogue, or at the beginning of the story. And are generally found in more paranormal/fantasy stories.
How do you avoid info dumps? The answer varies. When it comes to explanations of mythology, it may be best to have a prologue to show a bit of the mythology, or intersperse the information. Never drop a load of info at once, because the reader with a) forget everything by the end of the chapter or b) get seriously confused.
Another way would be the main character has visions that connect with whatever information is being given. Or tiny bits are revealed throughout the story, as I've stated before. People learn may different ways, so applying learning techniques may help, like providing information and then explaining the information later on.
Also, try to avoid info dumps at the beginning of a story. It will slow down the story, and its always best to start where the plot is. Info dumps are back story.
Fixing info dumps always requires a lot of though. Sometimes they aren't avoidable, but if they aren't, make sure to give little bits throughout the story. We don't need the reader developing a headache or throwing the book around when they're not even halfway through the book.