So you decided to write a series! Most people–even in the writing world–will call you crazy for embarking on this long and arduous journey, but the satisfaction of writing your story over multiple books and getting to know your characters and plot super well will be worth it in the end. But before you jump head-first into writing the first book, you need to plan your series–even if only a preliminary sketch that will most likely change over the course of writing the series.
I’ve only read one book on fiction series, and that was Writing the Fiction Series by Karen S. Wiesner. I highly recommend it for everyone, even people who aren’t writing a series because it speaks a lot about consistency, and everyone can use some more help with that. In addition to that, I really love The Complete Handbook of Novel Writing. It has great advice from many renowned writers. Both of these books I consider must-buys for all writers.
I’m a semi-plotter, semi-pantser. Or as Stephanie Morrill of Go Teen Writers says, I’m a “Plantser.” Let me explain. I start writing the first scene that comes to mind and keep going until I get stuck. Then I go back and re-outline. I do this for non-series books, too. But with a series, after outlining the whole first book, I go ahead and roughly outline the next and maybe 3rd book. If there’s more in the series, I may try and put something down for them too, but it depends. Then I go back and revise the first book to hint at what comes in the subsequent books (Karen Wiesner calls these “Series Plants” in Writing the Fiction Series, and honestly, they’re genius devices).
My process involves lots of revision, no matter how good the first draft is, because if I do something in the first, it will always affect the later books, and I go back to the later outlines to reflect that.
If you’re writing a series, you’re in it for a long haul. Don’t half-ass anything and cut corners. It will leave your story somewhat flat, and readers will lose faith in you incrementally as the series progresses unless you have it all together.