A good general (i.e., non-AI) introduction to linguistics and the nature of language, with a broad but fairly detailed coverage of the main topics in the subject. Includes sections on the historical, psychological, philosophical, and biological aspects of language, as well as good chapters on syntax and semantics.
An excellent introduction to natural language processing, with a good general opening chapter on language as a knowledge-based system, and covering all of the main approaches to syntax and parsing. Each chapter is supplemented with a number of very useful exercises. Winograd's idiosyncratic specialized representation language, DL, very effectively guides the reader towards the writing of natural language processing programs.
There is no book on semantics from an AI perspective that is easy reading. The above book, however, is a good general introduction to semantics, which includes clarificatory discussion of some of the semantic theory we have sketched out in the chapter, as well as quite an extensive overview of the main issues in pragmatics.
A massive (664 pages) volume bringing together key papers in all areas of natural language processing (syntax, semantics, discourse, speech acts, generation) together with descriptions of milestone natural language systems. Much of it is tough reading, but it makes an excellent reference and resource book.