There are a whole lot of books out there about container gardening. I know, because I've bought my fair share. I'll tell you which ones I've held onto and refer to frequently and as I come across new ones, I'll add to the list.
Gardens To Go: Creating and Designing a Container Garden by Sydney Eddison. This lady is just amazing. She has written numerous books on gardening but this one is, of course, my favorite. It covers all of the basics from choosing containers and plants to arranging, maintaining and overwintering. The picture of that rooftop garden on page 29 is phenomenal.
P. Allen Smith's Container Gardens. All of Smith's books are
beautifully produced and photographed.
This book contains "recipes" for containers that you can plant in each season.
He's not afraid to really cram the plants together so that you can have instant impact. I often look at his diagrams and think there's no way all those plants will fit, but they do and they look amazing.
Container Gardening by Paul Williams. This is a very practical guide that does a great job of showing you how to marry plants with pots. He schools you on color, texture and proportion. This would be the book I'd go to if I was trying to make a major style statement with maybe just a container or two (or three).
The Ultimate Container Gardener by Stephanie Donaldson.
This book is where I got the idea to use a wooden wine case as a container. She used hers to plant various herbs, which I have done in past years, but last year I also used one to grow different types of lettuces. The
book is filled with all kinds of creative projects and
includes step-by-step directions.
Container Plants for Patios, Balconies and Windowsills by Halina Heitz. I like this book's fairly comprehensive section on the myriad of plants that are suitable for containers. Unfortunately, it may be a bit difficult to find. It's available via various sellers on Amazon. Worth it if you can find it.