The Pacific Bonsai Museum just launched a Kickstarter for their next book. You can find the details here, A Gallery of Trees.
I bought their last book about their Natives exhibit (which is currently on sale) and if this book is as well done as that one, then it will be an excellent addition to your personal bonsai library.
Update: Looks like @sunnspot recently posted about supporting the museum and all the great work they do.