Before you set out to write a book (fiction or non-fiction), it’s always good to try your hand at that topic or genre in a shorter version. Writing anything book-length is a huge committment. Better to find out you hate that genre in a 5,000-word story than in a 100,000-word novel.
While you’re writing that story, test out your compatibility with the topic, the genre and all that surrounds it. When you’re writing a book, you’ll need to spend a good deal of your time researching the topic. Do you enjoy reading about the topic you’ve chosen? Are you so interested that you become lost in it and move from source to source drinking in the facts that you find? Or are you bored with it in seconds and can’t wait for the research phase to be over? Your reaction makes a difference. And finding out that you’re not all that interested after all is better sooner than later.
Time commitment is a huge factor in writing anything book length. A book can take months or years to write depending on the amount of time you spend on it daily. I found through writing during National Novel Writing Month, that I can accomplish a great volume of writing if I devote my life to it. When trying to write a novel in a month, I carry my writing with me everywhere and add sentences or paragraphs to it throughout the day. It takes some sort of scheduling to finish a book-length piece of writing.
So, think through your likes and dislikes and try out a few shorter pieces on your topic before you commit to going the distance.