I have used the Teach Yourself series for a number of languages and have been very happy with the results. As other reviewers have pointed out, this text desperately needs to have characters along with the pinyin. I incorporated that failing into the learning process by looking up every word with the Oxford University Press dictionary. But that was tedious at times. Although you can find most words with just the pinyin, proper nouns are especially difficult to transcribe with only a basic dictionary - and there are a lot of people and places in Beginner's Chinese.
The audio is a must. The track cuts out mid-sentence in Unit 4 (Saying how old you are). Apart from this minor glitch, the sound is good and the speakers are easy to understand.
If you are interested in learning how to read and write Chinese, you should get an additional text (Unit 11 gives a brief introduction).
The book is well organized and grammar/vocabulary prioritized around the needs of a beginning learner/traveler. The Teach Yourself series requires work, but is rewarding. Now that I have finished this text, I am working in Yong Ho's Intermediate Chinese (Hippocrene) and Schaum's Outlines. I am familiar with many of the grammar points and much of the vocabulary thanks to the Teach Yourself Beginner's Chinese.