How do I write a good book? I was thinking that I should write a few simple and criticism-free fantasy novels until I get the groove of my writing style, then I start the book I longed to write.

In my opinion I would ignore a lot of what Mercedes Lackey wrote. Creative genres are, by nature, subjective. So, what's a good book for one person might not be a good book for another person. I wouldn’t read Harry Potter if you paid me. I read a chapter and that was too much. Is it rubbish? No. It's just that I don't like it and don't want to read it but plenty of people think differently. Were The Beatles a good band? No, not particularly. Some of their songs are agonisingly repetitive but they happened to be in the right place at the right time and captured a market. The point is, everyone has their own opinion of what good actually is. For a book to be good I believe you need an original idea. Something different, something which taps into people's curiosity. By all means read respected authors, study their styles and use of language. However, don't think you have to abide by their rules. Write your book. Believe in it. Get other people to read it. Take their feedback. Improve it, proof read it several times. Get other people to proof read it several times. Finally you'll end up with a manuscript you're happy with. Some people will love it and some people will hate it. Don't worry because no one can write something everyone loves. Just like Directors can't make movies everyone loves and bands can't make music everyone loves. It's impossible because artistic genres are subjective. Write something original and what you believe in. There will be people who love it and just because sone people might not like it doesn't mean it's not good. William Shakespeare? Overrated. Harry Potter? Overrated. The Beatles? Overrated. That doesn't make my opinion right but remember that people who do rate them have their opinions too. And opinions are personal.