Here is a list of some books I've been reading lately that have been a huge help in my struggle to learn Japanese:

Making Sense of Japanese: What the Textbooks Don't Tell You, by Jay Rubin

This one is really great, especially the first couple of chapters ("The Myth of the Subjectless Sentence" and "Wa and Ga"). The wa vs. ga discussion was particularly enlightening and cleared up most of the confusion I had about these two particles. I really like this writer's style, his humor, and the way he makes the more confusing (to me, anyway) grammatical issues of Japanese seem almost ridiculously easy to grasp. Here's a quote as an example of the book's general feel: "As usual, official policies of the United States toward Japan are totally misdirected. Instead of pressuring the Japanese into lowering trade barriers or taking a greater share of the responsibility for their own defense, we should be urging them to bring their verbs from the ends of their sentences into second place, right after their subjects, where they belong. Unless we accomplish this, the rest of our foreign policy is so much tofu." Not an easy read by any means, but definitely a fun one. ^_^

Reading Japanese With a Smile, by Tom Galy

Another wonderful read. This one is a collection of nine stories from a Japanese weekly magazine, designed to help develop skill in reading Japanese. Each story is slightly humorous, which makes it more interesting than reading dry excerpts from textbooks. The stories each come with an English translation as well as a sentence-by-sentence breakdown that provides readings for every kanji along with grammatical notes. This has been the most exciting thing for me, because I'm actually reading Japanese now, and not just scattered words and sentences designed to instruct. It's a tremendous feeling of accomplishment to get to the end of a story and realize that I understood the entire thing. :)

Kanji in Mangaland, by Marc Bernabe et al

This is a wonderful study guide IMO. I'm still on Volume 1 because I haven't been studying near as much as I should lately, but it's an incredibly useful tool for self-study. I learn very well in a classroom environment, and the way these books are arranged into lessons works very well for me. Each lesson starts with a number of new kanji with associated vocabulary, then follows up with a one-page comic in Japanese using the newly learned words. At the end of the lesson is a short quiz that stresses not only kanji recognition but pronunciation. I'm using both the textbook and the workbook, which offers a full-length comic broken into blocks for each 5 lessons with various quizzes and exercises attached. One of the things I like best about this series is that it assumes the reader already knows hiragana and doesn't try spoon-feeding the romaji to us. So it's wonderful practice for reading hiragana as well as learning new kanji.