Does the book have an explicit statement that it is in the public domain? Was it published before 1923? Do you have a license or direct permission from the author to reprint the content? If not, then no, then it's almost certainly copyright infringement to copy the content and publish it on your blog. If you are looking for book content, check out Project Gutenberg, which has lots of books that are now in the public domain.
No, most encyclopedias are copyrighted so you cannot use them on your blog. You can use content from wikipedia as it is licensed differently assuming you cite your source. That said no one is going to go to your site if all you have is copied wikipedia content.
An encyclopedia isn't any different from any other publication. You need permission to reprint. MelogKnaj is right about Wikipedia (read their terms for reusers) - both that you can use the content and that visitors aren't going to be interested in going to your site if it's just a Wikpedia dupe. You could also reprint articles from the 1911 Encyclopedia Britannica, because that is now in the public domain.
You can use a select few quotes and site the source, but using like a paragraph out of it is illegal. Just rewrite it, is it that hard?
You can post a quote from it or paraphrase it, making sure to cite the source in either case. You cannot legally copy word for word, whether you give credit or not.
You have no permission to copy something from a book. But it will not cause problem to you If it is not a famous book!!! But it is illegal: Stealing articles. I suggests that it is not fair.
Quoting a small amount of text from a copyrighted encyclopedia and citing your source can fail under fair use. How much text you can quote isn't clearly defined; take a look at the Associated Press quoting controversy for an example of this.