Depending on what you read -- there is also a lot of misinformation from some who misrepresent it, don't understand it and/or are here for contrary purposes.

You will find most of what you need at http://campus.aynrand.org/ and http://estore.aynrand.org

Additional important books in the non-fiction category, emphasizing the comprehensive, systematic philosophical nature of Ayn Rand's ideas are:

Ayn Rand, For the New Intellectual, 1960
Allan Gotthelf, On Ayn Rand, Wadsworth, 2000 (out of print due to publisher financial problems, search for a used copy)
Leonard Peikoff, Objectivism: The Philosophy of Ayn Rand, 1991

Allan Gotthelf and Leonard Peikoff were associates of Ayn Rand and are experts on the philosophy. Leonard Peikoff founded the Ayn Rand Institute and is now retired. The late Allan Gotthelf organized and for many years ran the Ayn Society special philosophic interest group within the American Philosophical Society.

Ayn Rand's For the New Intellectual contains a major title essay and otherwise consists of excerpts from the more philosophical parts of the novels. From the preface:

[This book] "contains the main philosophical passages from my novels and presents the outline of a new philosophical system. The full system is implicit in these excerpts (particularly in Galt's speech), but its fundamentals are indicated only in the widest terms and require a detailed, systematic presentation in a philosophical treatise. I am working on such a treatise at present; it will deal predominantly with the issue which is barely touched upon in Galt's speech: epistemology, and will present a new theory of the nature, source and validation of concepts. This work will require several years; until then, I offer the present book as a lead or a summary for those who wish to acquire an integrated view of existence. They may regard it as a basic outline; it will give them the guidance they need, but only if they think through and understand the exact meaning and the full implications of these excerpts"...

"For those who may be interested in the chronological development of my thinking, I have included excerpts from all four of my novels. They may observe the progression from a political theme in "We the Living to a metaphysical theme in Atlas Shrugged.

"These excerpts are necessarily condensed summaries, because the full statement of the subjects involved is presented, in each novel, by means of the events of the story. The events are the concretes and the particulars, of which the speeches are the abstract summations. When I say that these excerpts are merely an outline, I do not mean to imply that my full system is still to be defined or discovered; I had to define it before I could start writing Atlas Shrugged. Galt's speech is its briefest summary."

"Until I complete the presentation of my philosophy in a fully detailed form, this present book may serve as an outline or a program or a manifesto."

"For reasons which are made clear in the following pages, the name I have chosen for my philosophy is Objectivism."

She never wrote the "presentation in a fully detailed form" for her philosophy in the form she described, but there are equivalents available. She published one part of the planned "detailed, systematic presentation in a philosophical treatise" she described above emphasizing "dealing with ... epistemology [to] present a new theory of the nature, source and validation of concepts" in her Introduction to Objectivism Epistemology, listed by Mike above. IOE is very important, but is not the place to start reading about Ayn Rand. It is almost exclusively on the nature of concepts (including the nature of the axiomatic concepts); the 2nd edition includes two appendices, one with Leonard Peikoff's essay on propositions, "The Analytic Synthetic Dichotomy", and the other with about a third of the workshops on epistemology she conducted to answer serious, detailed questions from a small group.

Leonard Peikoff's recorded 12-lecture course The Philosophy of Objectivism from the 1970s http://campus.aynrand.org/classroom/74/ systematically covers the whole scope of her philosophy in a far more philosophical manner in more detail than had previously been presented, and Ayn Rand was sometimes present to answer questions.

His own detailed treatise Objectivism: The Philosophy of Ayn Rand is based on that lecture series and expanded in more detail. It took the place of the major, comprehensive work that Ayn Rand had once intended to write herself. It begins with the metaphysical basis of the philosophy and the reasons for it, and the epistemology (but only summarizes the nature of concepts covered in detail in Introduction to Objectivist Epistemology), and continues to build systematically through the ethics, political philosophy, and philosophy of art: Look at the table of contents at https://estore.aynrand.org/p/522/obje...

His recorded Introduction to Objectivism is a brief, 1 1/4 hour summary lecture and question period. https://www.youtube.com/watch?v=hlJD0...

For those interested in Ayn Rand's philosophy, this tells you the most serious, systematic accounts to read and listen to -- along with many other essays not as technical, but very important in the topics they emphasize, such as "Philosophy: Who Needs It?", "Causality Versus Duty", "Metaphysical Versus the Man Made", "Philosophy and Sense of Life", and many more, included in the non-fiction books listed by Mike (and which also include Ayn Rand's own essential essays on the basic principles of ethics, politics and art).

Also crucial is Leonard Peikoff's lecture series on the History of Philosophy, which explains the historical development of the major philosophical positions, how they were connected and influenced one another, how they differ from Objectivism, and the Objectivist answer to philosophic problems in the historical context. http://www.galtsgulchonline.com/posts...

Allan Gotthelf's On Ayn Rand is much briefer as part of a professional series summarizing philosophers within 100 pages each. It covers the main features of Ayn Rand's philosophy, but organized differently, beginning with the famous Ayn Rand "sense of life". It is also very well written, but if you are not familiar with philosophy you may find some parts of it too condensed to appreciate the significance of all the points made.

Re-reading Galt's speech in Atlas Shrugged after going through this material will show you how much of the significance you missed on a first reading of Galt's speech without it, and more fully what Ayn Rand meant when she wrote, "The full system is implicit in these excerpts (particularly in Galt's speech), but its fundamentals are indicated only in the widest terms".

Recognizing Ayn Rand's works as a serious, comprehensive intellectual development, you can see why Mike said that liking Atlas Shrugged does not imply a knowledge of Ayn Rand's ideas. It's a full, systematic (and radically different) philosophy with a content of its own, it doesn't mean whatever other ideas or feelings people bring with them when they like the novel or become attracted to aspects of the non-fiction they happen to read. It doesn't mean the preconceptions of either its fans or its detractors (some of whom have an axe to grind). You can discuss it here or anywhere else, but there is no substitute for learning what it is first hand.

you really needed to add that last part, didn't you. can you not go one comment without being a pomp ass? :)

Wouldn't have it any other way!

Salty Dog, your have the simplicity and also the depth of Yoda. Agree with you, I do. Don't be afraid to read Rand in her own words, reread, until it becomes a part of you and you feel what she meant. I first studied her in philosophy class, transitioned to one of her fiction writings, one after another, and then to "Capitalism: the Unknown Ideal", and continued on, until my readings had filled a complete shelf, there to reference when needed. Although I did not understand everything she did, I did understand what she thought. I have copies of her interviews on tape, and even a few analysis by others she worked with, although, I do not like the once-removed way of relating. I truly believe there is something there form everyone if they just listen with their eyes. The catch is, start with what excites you and journey on.