You want to know more about the original publications of the inventors of quantum mechanics and read their own words? Then this large volume is very good value. Though what you get out of it will depend strongly on your technical background in physics and what you expect from your reading.
The selection of papers was presumably made by Stephen Hawking. If so, it is rather odd in that a number of key papers are missing. In particular Bohr's famous paper 'On the Quantum Theory of Line-Spectra' is replaced by a much later review article. No doubt this makes for easier reading but it is not in the spirit of the book as advertised. Again, the key paper by Born Heisenberg and Jordan 'On Quantum Mehanics' is not there, probably for the same reason. As usual in US/UK physics de Broglie's contribution is absent. Amazingly there are 2 long papers by David Bohm on his hidden variables interpretation of quantum mechanics (39 pp!) which has had zero influence on current physics.
The introduction by Hawking is a (very) brief history of the subject which seems to be present mainly to justify his name on the cover. It does not discuss the contents in detail. It also looks as if Hawking was not involved in the brief commentaries heading each chapter: these are attributed to Joel Allred. They will not help you to understand the papers. (If you want to know what can be done to explain the papers and their history in detail, look at '100 Years of Planck's Quantum' by Duck and Sudarshan or 'Sources of Quantum Mechanics' by van der Waerden.)
A largish proportion of this volume is taken up by review artcles and even a couple of chapters from a popular book by Gamow; hardly 'the most astounding papers ...' promised on the dust jacket. Even so, it does cover a large range - up to work by Feynman, Schwinger et al.
The book has a clear typeface, all papers have been translated and reset (expect typos) and it is nicely bound. So if you know some physics already - about degree level - it represents unbeatable value at Amazon's price. Get it for the price of a couple of drinks.100 Years of Planck's QuantumSources of Quantum Mechanics (Dover Books on Physics)