Question: 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.

Answer: 
I would wholly recommend Susan Blackmore's [Consciousness](http://rads.stackoverflow.com/amzn/click/B007PM2LW6). 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](http://organizations.utep.edu/portals/1475/nagel_bat.pdf). 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](http://rads.stackoverflow.com/amzn/click/0393334775). 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.