But I can't work on two novels or two non-fiction books at the same time. It gets too confusing. I really prefer to take them one at a time. My novels take about a month to research and plot, then another month to write and revise. Non-fiction books for kids usually take four months.
Kids are a much more appreciative audience.
None of my adult books have been very successful, and I don't write for adults anymore. No, I prefer writing on paper. I write my books on a computer, a Macintosh Powerbook. When I'm stuck, I find the best thing to do is break the rhythm. Take a rest.