If you didn't already know it, I'm planning an entire series about Ruby Ransome and her adventures with vamps. I already have ideas for future books, and I need to sit down and brainstorm one of these days to flesh some of them out and come up with more ideas — the first book takes place in 1923, so I need to see how many books I'm going to want to cram into the remaining 10 years of the decade. Some of the ideas I have take place in specific years — one of them in 1929 — so I really need to get an idea of all the books I want to have in the series before I get too far along. Initially I thought of doing a book per year, but most will cover fairly short periods, so maybe I should plan for more.
Anyway, Barnes & Noble's PubIt Facebook page linked to a very interesting article today, on dealing with continuation issues in a series. (The title is somewhat misleading — the article isn't really about continuation issues to avoid, but how to deal with the issues.)
I've already come up with ideas for my covers that I think will create a strong brand, so I'm good on number 4. I also have a very good idea of the overall story for the series (Ruby and Victor fighting vampire-driven organized crime in the 1920s), so put a check next to number 5. I also feel good about Ruby's character arc throughout the series, so we're good there too. And number 7 deals with what I was just talking about: planning out the series ahead of time, so that I can make the time line work.
Numbers 1, 2, and 3 are more about keeping the details straight. I'm actually not sure 1 and 3 aren't the same thing — 1 talks about getting character details right, and both 1 and 3 talk about rereading prior books to make sure you're remembering the details correctly. Personally, I keep an "outline" (loosely defined as such) with character information, and I try to add important details as I think of them. I may develop this to include more detailed character sheets for each one.
Two is a very interesting issue. Do you make each book a standalone? Do you repeat information in each book in order to bring up to speed the readers who are just now coming into the story? While I agree that books need to bring readers up to speed — for those who read the last book or books a while ago, as much as for those who have never read them — I think too much of this really bogs down the story, and in my books I'd like to keep it to a minimum.
I've written novels before (though never published), but writing a series will be a new adventure for me. I have to say I'm looking forward to sticking with these characters for a while!