W.V. Davies' book on Egyptian Hieroglyphs (part of the 'Reading the Past' series put out by the British Museum in cooperation with the University of California Press) is an excellent primer to the subject of this ancient language. Like the other texts in this series, the book itself is only 64 pages long, which makes the task of learning an ancient language like Egyptian Hieroglyphs less daunting. Do not be deceived by the low number of pages - there is a wealth of material here.
The first chapter gives a 'birds-eye view' of the language - Egypt was a kingdom which existed for many thousands of years; the language changed over time (just as Old English became Middle English became Modern English). The phases are Old Egyptian (2650-2135 BC), Middle Egyptian (2135-1785 BC), Late Egyptian (1550-700 BC), Demotic (700 BC - 400 AD), and finally Coptic. These stages are not set in stone - the development of the language over time was fluid. One of the difficulties of studying any of the language stages prior to Coptic is that there are no vocalic structures we can be sure of for any previous stage.
Davies explains in the second chapter that hieroglyphs have been found even hundreds of years older than the oldest known language structures, dating back as far as 3100 BC. The latest hieroglyphic inscriptions date from nearly 400 AD, giving this form of script a 'shelf-life' of three and a half millennia. Much in the way Chinese script is pictogramatic, so are Egyptian hieroglyphs based in pictorial representations, of which more than 6000 unique characters have been documented. Davies talks about the different ways of reading hieroglyphic writing and inscriptions, as well as the development of the script into Hieratic adaptation. The later developments into Demotic and Coptic scripts is also covered, but not fully developed (given the focus of this text, they need only be presented as future developments).
Chapters three and four are the heart of Davies' work on the language itself. Here are presented the general principles of writing (logograms, phonograms, determinatives, and basic vocalisation) as well as the introductory issues of grammar (gender, number, nouns and cases, prepositions and articles, proper names and dates). Not much is done with verbs - often people's interest in Egyptian hieroglyphs is to read inscriptions, so much beyond basic sentence structure is not required. Like other ancient languages like Hebrew, vowels are not primarily added to written words, so modern transliterations and vocal rendering are shells, guesses to a large extent.
The fifth chapter gives a brief and interesting history of the deciphering of hieroglyphs, dealing both with the personalities involved (principally Champollion, but others, too), the mechanics of deciphering, and of course, the Rosetta Stone. The final chapter deals with developments and influence of hieroglyphs beyond Egypt. Despite Egypt being one of the ancient 'superpowers', its writing system did not make much impact beyond the borders of Egypt, as another wide-spread script was preferred in many ancient cultures - cuneiform. Nonetheless, Protosinaitic and Meroitic scripts directly borrowed from Egyptian script, and influences may have been made on Cretan and Hittite written language forms as well.
Davies includes a useful bibliography, and gets full marks for including an index for even so brief a book as this. While this book is but the introduction to the subject, it is a great text for those who have interest in Egyptian hieroglyphs, ancient languages, or linguistics, but do not have the time or inclination otherwise to pursue a full course on the topic.