u would think it was as simple as opening it up and just doing it...but it can be a bit more complicated.
A work of fiction is that simple...you start by looking at the cover, front and back, to see if it connects with you. If it does, you do what the Red Queen told Alice- begin at the beginning and go on till the end. Of course, some of us like spoilers and we cheat by taking a peek at the end of the book even as we are reading the beginning...but that might just be me.
A work of non-fiction is another thing altogether. Roughly non-fiction books are of two types. One end of that continuum is the 'book of facts' at the other end is the 'book of ideas'.
Books of facts are historical or procedural, encyclopedic-- they present details, facts, about someone or something in some kind of set order. Either chronological or some conceptual order- say from the outside delving inward or the inside bursting outward. Biographies and historical books are two of the most basic form of the book of facts and both use chronology to lay things out. A textbook or a encyclopedia are two other basic forms of the book of facts.
How to books can be in the middle of our continuum as they will present an idea, perhaps one single major thematic idea and then show how it works or developed by presenting facts to bolster that argument/presentation.
A true book of ideas offers up a concept, usually original, or at least the author believes this insight is a new one and then uses facts to persuade you that the idea is valid.
In both of the non-fiction type of books, you don't really need to get all hung up with reading it from page 1 till the end. Actually, you should be willing to playfully peruse the contents. Bouncing around and meandering amongst the pages. The author definitely had a plan, and laid it out in the sequence of chapters that the book presents. But, you are not the author and you might have a different idea how to learn. You should not be so confined by the form and structure that you find laid out before you. A good book of ideas will work even when you meander through it. Let your intuition and thus your fingers do the walking. A good book of ideas will germinate within you and will work even if you meander around.
A good book of ideas should never be read as if you have to memorize in detail what is being presented. Nor should you have to worry about getting it totally comprehended at the first go round. If you come upon a difficult passage, don't slow down! Speed up! Race through that complex mess or mass of words like you were running through a forest or swimming upstream. Plow through and don't look back. Your unconscious will absorb what it can as the words run by you even if you consciously don't seem to be taking it in. If the author was a deep enough thinker and a good writer, the ideas will sneak in, seeping through the dense consciousness and lodging and waiting like seeds to germinate later.
A really good book of ideas is one that you read fast through and then put it down. You got what you can--this time around. Let it sit on the shelve. If it really contains something worthwhile, it will call to you with the passage of time. You will start to feel and hear the ideas resonating in your mind and you will want to and feel the need to go back to that book. You will find on the second, or third, or X time you re-read it that somehow the author improved in her writing and things are clearer now than when you first read it. She just did a better job writing this book when you re-read it. Things hard to understand will now seem clearer.
So, don't be discouraged. A good book of ideas can and will change your life. Just don't let it stop you and don't think you have to memorize or understand it all the first time around. If it doesn't seem relevant to you, then your unconscious will just not bring you back to that book.
But if it was relevant, you will feel compelled to go back and re-read it and re-explore its topic and presentation of ideas.
Enjoy and may you always find your way.