I am writing a non-fiction book and I notice that in some books I am reading on the same subject, has similar 'information'. Not all but some. But, I am writing it differently and I have gone into further detail with particular things, plus I aim for it to be a different target audience. But, is it okay to include similar concepts in the book? For example, I could be writing about how to cook chocolate cakes and another author, or multiple authors have written the same sort of thing but differently.
Well it just seems to me like you'll be in a potentially crowded market. Then again, if you're targeting a different audience, then you may not have much competition. Still, I wouldn't worry about righting on topics that have been done before in non fiction. Almost everything under the sun and beyond has been written about. If anything, I'd be conscious of it being done though.
Before you start writing a book seek for, is there any similar subject in the books. I have this problem in the invention and designing theme. I often have invented something and then saw another person has made a device similar to it. An engineer recommend me, before I start designing an idea I refer to the internet and investigate, is there any similar device to my idea? And if not, I continue designing.
95, Information is free for the taking - it's how you present the ideas that you have to watch for. Using the same phrases/sentences/paragraphs (without giving proper credit) as the others would be a problem. Likewise, copying the look and feel of the other books might cause trouble. Simply using the same information is fine. In non-fiction, it's even expected. A non-fiction writer is presumed by the public (rightly or wrongly) to be an expert on the matter, and to have researched the subject and either distilled or expanded upon the information already out there. A good practice is to take notes as you read books on the subject in question, including the book/author. That's especially useful when you come across little nuggets of info that nobody else seems to have. Being able to say "According to XYZ..." both makes you sound as well versed on the subject as you really are, and insulates you some should the info eventually turn out to be inaccurate. I do applaud you for trying to become well versed on your subject, by the way. I know some corners of non-fiction have pretty bad quality control (*cough* cookbooks *cough*). Good luck. -Frank