These are some books I have bought or borrowed.

Oxford Started Chinese Dictionary ( ISBN 0-19-860258-8 ) Oxford University Press
This is a great book. It is a bilingual dictionary (it has both Chinese to English and English to Chinese). The lettering (type face) is very large, and the word entries are bolded and in blue, making it very easy to read and quick to look up things.
It has sections for new students on tones, how to write characters, what are (almost) all the measure words, etc.
There are many half or full pages within the dictionary sections devoted to a single concept, such as "not".
Chinese - An Essential Grammer by Yip Po-Ching and Don Rimmington ( ISBN 0-415-13535-4 )
This is an excellent book (about 220 pages) with a very clear explaination of nouns, sentences, grammer rules, etc. It also has a back section with all of the vocabulary discussed in the book. This includes many of the "difficult" words in Chinese. The entire book is in Pinyin, which makes it very accessible.
Chinese Idioms Volumn 1 ( ISBN 0-89346-289-6 ) -- part of "Peng's Chinese Treasury"
This is a small pocketbook (abour 140 pages) with a single saying or "idiom" per page. Each page has a cartoon drawing, a meaning, and an example. Some pages also have a "literal" translation.
The sayings themselves are printed in both Hanzi and Pinyin. Unfortunately, the examples are only in Hanzi.
It's an interesting book, but I wouldn't recommend buying it. There are many resources on the web that are better. Try searching Google with the words "Chinese idiom", for example.