In “Cool Japan Guide,” a cute (or, as maybe more appropriate here, kawaii) and accessible illustrated travel guide, cartoonist Abby Denson offers a lot of fun and useful tips for your first trip to Japan. Some of the advice may be a little common sense, but the book provides a lot of helpful basic information for planning for your trip, from getting ready to leave, to logistics, to leaving. In particular, it is geared to all of the standard Japanese activities tourists (especially tourists from a specific, slightly nerdy background) would be interested in and thus focuses mostly on Tokyo, Kyoto, and Osaka, and the temples, Onsen, and museums you can explore. The author, also, devotes a particular detail to food and shopping you can check out.
While not the most exhaustive treatise, this slim comic gave me plenty of ideas as I begin preliminary planning for my own Japan trip later this year, and following Denson's trips really is getting me excited for my own explorations. In any case, a good place to start without being overwhelmed.