[slightly updated reprint]
A. It depends on your interest.
a) An easy avenue to consider as a start would be to get some recent issues of Landscape Architecture Magazine which is published by the American Society of Landscape Architecture and is meant as their semi-official portrayal of the state of the profession.
Ian McHarg's Design With Nature and A Quest for Life.
Duany, Plater-Zyberk, and Speck's Suburban Nation: The Rise of Sprawl and the Decline of the American Dream.
James Howard Kunstler's Geography of Nowhere: The Rise and Decline of America's Man-Made Landscape.
Oh, what the heck. Maybe you should just pick from Planetizen's Top 20 Planning Books list for this stuff. (Or their latest, the Best of 2020)
c) For those who are trying to move up from entry level students to serious students of landscape architecture, here is an edited version of the list Dr. Shearer prepared for some our past design students:
John Stilgoe, Outside Lies Magic. Relatively short and very approachable, this book was written for a broad audience and intended to get everyone to go outside, look around, and think about the implications of what they see. For example, how does the US Post Office organize space and how, in turn, do we--in part--live by that organization?
John Stilgoe, Landscape and Images. This book is a compilation of some of JRS' articles and essays. Topics include the role of photography in shaping our understanding of the landscape (for better and worse), the specter of hobgoblins in suburbia, and bikinis. This book came out last year through the University of Virginia Press and I do not know if it is available as a paperback yet.
Simon Schama, Landscape and Memory. Schama is another historian, but unlike Stilgoe does not focus on the environment. (For example, a previous book was on Dutch painting and he has recently been compiling a multivolume history of the Britain.) As a result of his range, he is not as insightful on particular points about landscape change, but his breadth makes connections that a more specialized mind might miss. Some of the places described in Landscape and Memory will be familiar to you from your landscape history class; others--like Mount Rushmore--you will know from elsewhere. What I think is useful about this book is its organization: Rather than go through a discussion of these sites by time or by location, it is arranged in three parts by material: wood, water, and rock. This perspective can help you re-think not only what you learned in your history class, but how you might apply design themes based on materials in studio.
William Cronan, Natures Metropolis. If you are looking for patterns in this list, Cronan is also an historian. If he has a fault, it would be that he occasionally sentimentalizes some activities associated with shaping the environment. That particular problem is not so evident in this history of Chicago in which he describes how the idea (the promise?) of "progress," natural resources, and technology combined to create a new kind of urban condition. I recommend this book not because I think everyone should know about America's second city, but because it lays out, in clear language, how possibilities can be combined to create something bigger than most people can imagine. Whether or not such things should be built is another question, but it is happening at a rapid clip in China as you read. Admittedly, this book will be of more obvious interest to those in the environmental planning & management program, but it could help everyone think about the built environment.
J. Nicholas Entrikin, The Betweenness of Place: Towards a Geography of Modernity. This book is not an easy read: most graduate students need to keep a very good dictionary at hand, and you will want to (or need to) pause and think about what is expressed after each and every page. In essence, Entrikin tries to synthesize two opposing ways we understand the creation of regions. On the one side, there is the German "science of space" view which holds that law-like forces of change operate universally over time. On the other side is the French, "description of place" view which holds that regions emerge from entirely idiosyncratic opportunities and decisions. If you can get through it, it will help you to understand arguments of geographic limitation-determinism.
Gaston Bachelard, The Poetics of Space. If you pick up Kevin Lynch and Gary Hack's Site Planning, you will be able to start applying what you read very quickly; It's just that kind of book. The Poetics of Space is the opposite in term of easy application, but it is arguably as important. You do not "use" this book. Instead, you live with it, and as you do it infuses your own ideas and makes them richer. Most of the points are made in terms of architecture—and indeed, this book is read by just about every architect at some point in his or her education—but do not let that get in the way of you reading it. (Stilgoe thought it important enough that he wrote an introduction to one of the more recent editions.)
Niall Kirkwood, The Art of Landscape Detail and Weathering and Durability in Landscape Architecture. Kirkwood now deals with bioremediation and other technologies for brown field sites, but his first book and follow-up were careful studies of construction details. On the surface, they are about what combinations of material and forms work, what do not work, and why. However, their underlying premise is that for site scale design to be successful, the ideas of the larger scheme should be expressed in the thoughtful execution of the smallest elements. Admittedly, most books on building details are hopelessly dull and this text might suffer a certain lack of glamour. But if you want to further explore how a curb or a flight of steps might matter and, moreover, how thinking about these things might contribute to a richer design process, then these books are worth a look. Also of note, when I last looked, they were quite expensive.
James Corner [Editor], Recovering Landscape: Essays in Contemporary Landscape Architecture. Corner was the Chair of the Landscape Architecture Department at the University of Pennsylvania. Some of the essays in this collection are difficult to read, but if you are interested in wrestling with big ideas, it is a good place to start.
Malcolm McCullough, Abstracting Craft: The Practiced Digital Hand. During pin-ups and reviews we have talked about how the making of drawings and models is a matter of craft—of knowing about the qualities of materials and how they can be shaped for a certain effect. Very soon you will be making representations with a computer in addition to with a lead holder and chipboard and you might be wondering, is there such a thing as "digital craft"? After all, most AutoCad plots look as if they could have been made by anyone any time. McCullough, who was trained as an architect and urban planner, thinks that digital craft does exist, even if the ideas of craft are not discussed or taught in a computer lab. This book places digital media within a larger context of visual arts. It will not teach you how to make the most of the Photoshop magic wand tool, but it will introduce you to a way of thinking about your efforts with keyboard and mouse that will lead to better works.
Douglas Cooper, Drawings and Perceiving: Life Drawings for Students of Architecture and Design. Cooper teaches at Carnegie Mellon and this book might be considered a translation or adaptation of the well known The Natural Way to Draw by Kimon Nicholaides for designers. The instructions and exercises are quite good.
Robert W. Gill, Basic Rendering. This book is all about black and white rendering. Its strength is its discussion of how light behaves on the objects around us. It will help you to become a master of stippling.