"... For beginning players, [Discovering Chess Openings] will offer an opportunity to start out on the right foot and really get a feel for what is happening on the board. ..." - FM Carsten Hansen (2006)
https://web.archive.org/web/20140627114655/http://www.chesscafe.com/text/hansen91.pdf
Detailed suggestions are provided by Moret in his My-First-Chess-Opening-Repertoire books.
https://www.newinchess.com/media/wysiwyg/product_pdf/9033.pdf
https://www.newinchess.com/media/wysiwyg/product_pdf/9050.pdf
https://chessbookreviews.wordpress.com/tag/vincent-moret/
Opening Repertoire 1 e4 and Keep it Simple 1.e4 are somewhat similar sorts of book.
https://www.newinchess.com/media/wysiwyg/product_pdf/7819.pdf
https://www.newinchess.com/media/wysiwyg/product_pdf/9068.pdf
Openings for Amateurs by Pete Tamburro (2014) combines explanation of principles with starting opening suggestions. Of necessity, his opening descriptions are less detailed (than those of Moret) because he tried to offer choices to the reader and give some indication of how a player might choose what to try.
http://kenilworthian.blogspot.com/2014/05/review-of-pete-tamburros-openings-for.html
https://chessbookreviews.wordpress.com/tag/openings-for-amateurs/
https://www.mongoosepress.com/catalog/excerpts/openings_amateurs.pdf
Some players may not like the idea of relying on the limited selection of an author. It is a pretty daunting project to try to learn a little bit about a lot of openings, but, if one wants more freedom to make choices, it would make sense to look at a book like Yasser Seirawan's Winning Chess Openings.
https://web.archive.org/web/20140627132508/http://www.chesscafe.com/text/hansen173.pdf
While reading such a book, don't forget that the primary purpose is to get help with making choices. Once one has chosen openings, I again think that there is wide agreement that the way to start is by playing over sample games. Some of us think that it can be useful to use books like First Steps: 1 e4 e5 and First Steps: Queen's Gambit
https://www.newinchess.com/media/wysiwyg/product_pdf/7790.pdf
https://www.newinchess.com/media/wysiwyg/product_pdf/7652.pdf
as sources of games with explanations intended for those just starting to learn about an opening. Be sure to try to use the openings in games in between sessions of learning. Most of the time, one faces a position with no knowledge of a specific move indicated in a book. One has to accept that as part of chess, and think of opening knowledge as a sometimes helpful aid. After a game, it makes sense to try to look up the moves in a book and see if it has some indication of how one might have played better in the opening. Many opening books are part explanation and part reference material. The reference material is included in the text with the idea that one mostly skips it on a first reading, and looks at an individual item when it applies to a game that one has just played. Resist the temptation to try to turn a book into a mass memorization project. There are many important subjects that one should not neglect because of too much time on opening study.
https://www.chess.com/article/view/learning-an-opening-to-memorize-or-understand
https://www.chess.com/article/view/3-ways-to-learn-new-openings
https://www.chess.com/article/view/how-to-understand-openings
"... Overall, I would advise most players to stick to a fairly limited range of openings, and not to worry about learning too much by heart. ..." - FM Steve Giddins (2008)
"... I feel that the main reasons to buy an opening book are to give a good overview of the opening, and to explain general plans and ideas. ..." - GM John Nunn (2006)
"... If the book contains illustrative games, it is worth playing these over first ..." - GM John Nunn (2006)
"... the average player only needs to know a limited amount about the openings he plays. Providing he understands the main aims of the opening, a few typical plans and a handful of basic variations, that is enough. ..." - FM Steve Giddins (2008)
"... Everyman Chess has started a new series aimed at those who want to understand the basics of an opening, i.e., the not-yet-so-strong players. ... I imagine [there] will be a long series based on the premise of bringing the basic ideas of an opening to the reader through plenty of introductory text, game annotations, hints, plans and much more. ..." - FM Carsten Hansen (2002)
https://web.archive.org/web/20140627055734/http://www.chesscafe.com/text/hansen38.pdf
"The way I suggest you study this book is to play through the main games once, relatively quickly, and then start playing the variation in actual games. Playing an opening in real games is of vital importance - without this kind of live practice it is impossible to get a 'feel' for the kind of game it leads to. There is time enough later for involvement with the details, after playing your games it is good to look up the line." - GM Nigel Davies (2005)
"... Review each of your games, identifying opening (and other) mistakes with the goal of not repeatedly making the same mistake. ... It is especially critical not to continually fall into opening traps – or even lines that result in difficult positions ..." - NM Dan Heisman (2007)
https://web.archive.org/web/20140627062646/http://www.chesscafe.com/text/heisman81.pdf
The itch for opening study is intolerable 😎 I suggest the Scotch Opening 1.e4 e5 2.Nf3 Nc6 3.d4 This is a good start.