(Note: I originally reviewed this book as compared with the very similar Lonely Planet Pocket Los Angeles -- both books do a good job of giving an overview of LA activities in a pocket-sized format, but they would be more useful for different audiences.)
Frommer's Los Angeles Day by Day is pocket-sized -- slim but taller than a mass-market book, with a large fold-out map in a pocket inside the back cover and several other maps of specific areas in a three-panel fold-out from the front cover.
It's organized by interest rather than geographically, with chapters on shopping, dining, lodging, nightlife, outdoor activities, and arts & entertainment. But it opens with the author's curated "best of" recommendations -- first, suggested itineraries for one-, two-, or three-day trips, and then a half-dozen specialized day trips for particular interests (fans of movies, architecture, rock music, art, shopping, eating, or those traveling with kids). Assuming that Mueller's expertise is what it should be -- and any of us would have to be LA experts to seriously dispute it, I suppose -- this is the most useful part of Day by Day, giving travelers a template to start from when they plan their days in LA.
It has a crisp, authoritative look, with "tabs" for each section embedded in a color bar to make thumbing through easier, and there's a lot of color photos, though many of them are presented postage-stamp-size. The two-column layout presents a lot of data in a way that keeps it all easy to follow, and occasional sidebars give more detail on specific points.
The bulk of the book is written in capsule-review style, like listings in Time Out -- entirely useful, highly factual, but a bit dry to read straight through. The day-trips are more lively, with more anecdotes and factoids to spice them up. But this isn't a book to be read straight through to begin with; it's meant to be a reference and a guide, with each reader gravitating to the sections that she is most interested in. And, for that, it's very usable, with good maps embedded in the text to show where various places are in relation to each other. This book would be a bit bulky for a pants pocket, but it could easily go into a jacket, purse, or glove compartment for a trip around the city. Between the maps and the curated tours, it's an excellent (and clearly opinionated) guide to LA.