Heinlein's book is considered a classic in the genre. I have not seen the movie, but everything I've heard is that it bears only a passing semblence to the book (the title and the bugs).
The book is mainly set in boot camp and in the classroom (truth!). There are only two extended combat sequences in the entire novel - the beginning and the end. It's mainly a political and sociological treatise. I don't agree with everything Heinlein wrote in it, but some of it is downright prescient (and scary). In the book, he predicted the rise of predatory urban street gangs in the USA (remember, the book was written in 1959!), and that the Third World War would be the Russians, English and Americans vs the Chinese. Definitely food for thought....
