I'm looking for a book that isn't too dense and that is usually recommended for someone who wants to learn of the mind/consciousness but doesn't know where to start.
I would wholly recommend Susan Blackmore's Consciousness. It's part of the Very Short Introduction series, not as expensive as Blackwell's, and takes you through just enough history to help you understand what the relevant issues currently are. If you're interested in reading further, just check her citations and go from there.
Also, a good essay to start with is always Thomas Nagel's "What is it Like to Be a Bat?" which you can easily find online. Hume and Berkeley are worth reading, but they're a little removed from the current state of the debate on minds and consciousness. If you want something that's not dense, but you're not afraid of a longer read, there's also Stephen Pinker's How the Mind Works. It's a fairly strong Functionalist account of mind, but it doesn't pretend to have all the answers.
To be honest, it is hard to recommend a single book. If you really want to understand philosophy, you must read many books. So you might want to start with Hume's Enquiry Concerning Human Understanding, Berkeley's Treatise Concerning the Principles of Human Knowledge, Descartes' Meditations and Discourse on the Method, as well as Kant's Critique of Pure Reason and Principles of the Metaphysics of Morals. These are by far the best epistemology/metaphysics books I have ever read. It might seem obvious recommending such well-known books, but they are well-known because they are truly phenomenal. Also, if you are interested in the development of mathematics, and in particular analysis, I would recommend The Analyst by Berkeley -- a remarkable book. If however, you do not have time to read them all, start with Hume's Enquiry Concerning Human Understanding and Berkeley's Treatise Concerning the Principles of Human Knowledge, and avoid Kant' Principles of the Metaphysics of Morals, and any of Kant's books because they are very difficult to read. You need to read each book at least twice to understand Kant.
The most accessible book I have read on consciousness was The Mind's I, by Dennett and Hofstadter. It was a series of science fiction short stories that illustrated various thought problems in consciousness, followed by the two authors discussing the implications of the story. For someone just getting their feet wet in philosophy, it is a great easy introduction.
The best single book on philosphy of mind I have read is Blackmore's A Very Short Introduction to Consciousness. It is VERY SHORT, with very clean writing. It is also focussed on compiling the evidence that has a bearing on the viability of consciousness theories. Blackmore takes one through this evidence, and with a general dialog between dualism, materialism, and her preferred delusionism viewpoint. Blackmore would probably be best read after one has at least skimmed a general overview book on philosophy of mind, although one could read her first, then the overview second.
I have been studying (in my on spiritual quest) the topic of consciousness for more than a decade and I find that most of the stuff on consciousness severely lacking for two reasons. 1) it is too scientific and 2) it is too New Agey. I stumbled across a book last year that was a free download by an unknown author and the book just blew me away. The book is called "Demystifying the Mystical" by Endall Beall.
A few months back I saw that this author has created a series called the Evolution of Consciousness and I immediately purchased the books through Amazon. The first book is good and it takes on Philosophy and brings a new light to the field. The second book is called Willful Evolution and it makes so much sense and is more practical, not scientific or New Agey. Actually and the Demystifying the Mystical book (which demystifies what most people think of as mystical) so it kind of tears the New Age apart (with good reason). There are more books to the series that I am looking forward to reading.