Introduce your main characters and themes in the first third of your novel. If you are writing a plot-driven genre novel make sure all your major themes/plot elements are introduced in the first third, which you can call the introduction. Develop your themes and characters in your second third, the development. Resolve your themes, mysteries and so on in the final third, the resolution.
Michael MoorcockArthuriana has become a genre in itself, more like TV soap opera where people think they know the characters. All that's fair enough, but it does remove the mythic power of the feminine and masculine principles. So I prefer it in its original form, even if you have to wade through Mallory's 'Le Morte d'Arthur' - people smashing people for pages and pages! It still has the resonances of myth about it, which makes it work for me. I don't want to know if Mordred led an unhappy childhood or not.
Michael Moorcock