"An essential guide to Singlish" is a small book you can find in e.g. the Singapore airport. (at the time of this review, its not available from Amazon). This small book describes common words and phrases in Singaporean English. I'm not a native Singaporean, but do live in Singapore and this book reflects (in a funny way) the kind of English that is commonly spoken in Singapore.
The book consists of three parts. The first part contains common words used in Singlish in alphabetical order. It clarified the meaning in proper English and gives some examples. (unfortunately, it doesn't give you a guide on how to pronounce it). The second part contains tips about things to do and see in Singapore mixed with more sentence-like phrases which are commonly used. The third part contains addresses of places such as shopping malls etc.