The coffee house book is just the first in a collection of books I'm writing. The next book will be the funeral book, and the book after that will be the wedding book. (There are others planned, as well.) The books are not a series, but they do go to together.
Since the coffee house book is the first book I'm writing in this collection, I'll use that as the "foundation" for talking about the rest of the books. However, please know that each book is a stand-alone book. I could just as easily have started with the funeral book, the wedding book, or one of the others.
The books in this collection are all set in the same small(ish) town, with the different books presenting a different aspect of the town. And since it is a small(ish) town, some of the same people will be involved in those different aspects. For example, one of the coffee house characters is also a mourner at the funeral. In the same way you run into your friends and neighbors at the grocery store, you'll see some of the same characters appearing in different books.
The connection between the stories in these books, other than the overall setting, is the people in them. It's the people that make up the town, after all, and this collection is about the town.
So I've been faced with the prospect of connecting these books through the characters, while still allowing the individual books to stand on their own stories. I've discovered that the only way to do that is for each character to have an equal voice in the book(s) he or she is in.
For example, Shawn is a character in the coffee house book. He's a musician who uses the coffee house to escape a difficult situation at home. He's also in the band at the wedding reception. These two separate books reveal different aspects of his story, but just because he's already in the coffee house book doesn't mean his section in the wedding book will be any less significant. It's a different (sub)story about the same character.
This is another reason my character biographies are so detailed and so important. Different aspects of characters will appear in different books, so those aspects all have to be in the character biographies. By creating the same detailed biographies for all the characters, I'll be able to draw any character for any book for any other book.
What's interesting is that as I'm working on character biographies, I'm finding more connections among my characters that I didn't think of before, and these connections will work well as I build the world of this collection.
It's going to take a lot of work throughout the whole process, but I know it will be worth it when readers can connect with the characters I've created.
How do you create well-rounded characters for your stories?