This is probably the best introductory book out there to learn the Burmese language. The audio recordings are extremely helpful to get the tones correct. John Okell does a thorough job of explaining the usage and pronunciations of all the consonants, vowels, and the different rule exceptions. It is good for self-study, but will be better if one can find a native Burmese speaker to help if there are questions.
A word of note: There is a new edition out with the same book, but with a CD instead of audio cassettes. Look for that version on the internet unless you prefer audio tapes.