I'm a first-year computer science student with very little "real" programming experience who had to learn Ada95 for the introductory CS course. I'm guessing you're in a similar boat if you're reading this review, as Ada is a fairly obscure language. The author wrote this book for us in mind though. Although this book is for learning Ada, you'll also learn basic CS concepts that are just expressed differently in other languages. If you like the Headfirst series with lots of graphics and funny side comments, then you won't enjoy reading this book. The John Barnes book is better suited for people with programming experience or are looking for a reference on Ada syntax.
For example, in Skanholm's book, there is a chapter defines the general ideas of inheritance and polymorphism and then illustrates how these concepts would be expressed in Ada with various data structures. The chapter on dynamic data structures briefly describes trees and tree-traversals, which you'll have to learn anyway, and then uses these data structures to elaborate on the idea of pointers as used in Ada. The pointers were hard for me to grasp because he made no analogy, but rather Skansholm explains it quite simply in terms of memory allocation. Variable scope is another area that could have had more explanation or an exercise to test our comprehension.
The tone of this book is rather straightforward and tends on the dry side, but not to the point where it's detracts from comprehension. The structure of his writing might have helped. For example, when introducing a new data structure, he'll reference back to the data structure we just learned and explain how the new data structure addresses these limitations. It helps then, to read each chapter from beginning to end, as each subsection in the chapter usually starts off by referencing what was presented in the previous subsection. I can't judge the order of the chapters though; it seemed a bit jumpy in the beginning. But the index is pretty detailed if you want to look something up. There aren't many graphics or figures. Those that are included aren't always so helpful either, particularly in the section on recursion.
However, you'll learn the most from actually writing code, and for that there are a good variety of exercises at the end of each chapter. And the best part is that the solutions are available on his website for download. So you get good feedback (just that the code commentary is in Swedish--not too hard to figure out though) Some exercises require you to write just a function; others ask for a program with multiple steps and blocks. Most exercises are either on the mathematical side or are "real" world problems. For example, you are asked to write an implementation of the Maclaurin series to calculate e^x, as well as to calculate wages of employees or organize bus tours at a travel agency. It would have been nice if he had questions to test your conceptual understanding of a variable versus a parameter versus a pointer.
There are a few typos from what I noticed, but they don't detract from understanding, and I believe you can get the errata from the author's website. All in all, this is a good book to get when you're a student who has to learn a language that you'll never probably use in a real-life work environment...
