Most of these excercises and hints I've gathered from other authors, classes, books, and personal experience from my own rocky writing journey.
Getting to Know your Characters
-Interviews: ask your characters about themselves; it's helpful for me to imagine how they would respond and reveals a lot about their personality. Also, how do they say it; straight-forwardly, nervously, angrily, etc.
-Super-heros: compare your characters to a super-hero they are most like. Why that one and not another?
-Animals: what animal is your main character like and why?
-Fruit: same as the two above. I compared one of my mc's to a watermelon because she is hard to crack, but once you do, you find there is sweetness inside her.
-Physical Traits: don't forget to know what they look like, even down to what size shoe they wear.
-These details probably won't make it into the novel, but they're helpful for me to know them better. I also like to find pictures that look like them so their image is even more imprinted on my mind.
-Where and when does the story take place?
-It's important to know not just what the land is physically like (geography), but culturally too.
-What is the government like? Are there big cities? What kind of technology is there? Do the people in your world celebrate certain holidays?
-Most of these details will not make it into the novel either, but they are important to answer before you write the story so that you have a foundation for your tale and the readers can picture the landscape (of course, if you're writing about the U.S. today, it's not as crucial to answer all these questions).
-Looking at maps is also helpful in creating your own world for names of possible cities, rivers, etc, as well as how getting an idea of what different landscapes look like.
-Don't forget about the details! Are the buildings made of brick or clay? Is their deer in the country or just annoying prairie dogs? What kinds of plants grow around the area? This makes the setting even more real to the reader. And the more real it is, the more they won't want to leave.
Plot vs. Flashback
-I'm struggling with this a lot myself, so I don't have a lot to say. But don't underestimate flashbacks! They can be a good way to grab a reader emotionally while portraying information in a interesting way.
Some Good Books on Writing:
-On Writing Well by William Zinsser: Good for writing non-fiction, as well as how to improve your writing skills.
-Writing Books for Young People by James Cross Gibling: Discusses what is needed to write for a younger audience, both for different kinds of picture books and YA novels.
-Is Life Like This? A Guide to Writing Your First Novel in Six Months by John Dufresne: I didn't actually write a novel in 6 months with this book; we used it in class, but it has a lot of good writing exercises for everything from plot, setting, getting to know your characters, editing, etc.