welcome to the site. i look forward to other people's responses to your question.
because this is an anarchist site, the tag "anarchy" is useless here. perhaps you could change the tag to something more indicative of your interest, like - authentic, or historic, or introduction (or all of the above, depending on what you mean by "true anarchism")?
have you looked around on this site already?
also search for introduction or introductory on theanarchistlibrary.org
and check out littleblackcart.com
introductory books are berkman's the abc of anarchism; peter gelderloos' anarchy works; colin ward's anarchy in action, but really there are enough of these kind of texts that having more information about what about anarchy interests you would be more helpful in giving you specific titles.