I'm sure that the book that Sally recommends is a good book generally as well as for learning about the concepts and notions of SFG especially, but I'd imagine that the following books would all be more comprehensive (note that I've included one, the Downing & Locke, that is also SFG-related; another possibility for an SFG course if not reference grammar however could be Graham Lock's
Functional English Grammar), and any of the asterisked can be used as reasonably detailed reference grammars. Bear in mind that the Leech, Biber, and Kennedy all share pretty much the same terminology (i.e. that derived from the Quirk stable of grammars), but that the Leech and then the Kennedy are likely to be the gentler/less overwhelming of the three. All the books with the exception of the Biber (which requires a separate Workbook, not that the LSGSWE itself doesn't have any recaps, summaries etc) include exercises, whilst
The Grammar Book in addition devotes some space to suggestions for activites (not all of them that good however LOL), and is useful for its frequent distillations of discourse-level research (i.e. how the demands of extended discourse [beyond the level of the isolated sentence] often influence or indeed dictate grammar choices). Lastly, note that the Biber is often interesting for its comparative data drawn from four registers (conversation, news, academic prose, and fiction). I guess the books I feel most inclined at the moment to actually sit down with and take notes from though are the SFG-inspired Downing & Locke, Lock, and COBUILD Grammar, and the three general grammar dictionaries mentioned in the penultimate paragraph of this post.
Leech et al's
English Grammar for Today (Second Edition)
Huddleston & Pullum's
A Student's Introduction to English Grammar
*Biber et al's
Longman Student Grammar of Spoken and Written English, plus
Workbook (sold separately)
*Larsen-Freeman & Celce-Murcia's
The Grammar Book: An ESL/EFL Teacher's Course (Second Edition)
*Downing & Locke's
English Grammar: A University Course (
http://books.google.com/books?id=8ii6JX ... frontcover )
One course-like book that covers more than grammar (i.e. articulatory phonetics, phonemes, morphology, discourse too) is Kennedy's
Structure and Meaning in English: A Guide for Teachers. You can preview this, the Huddleston & Pullum, the Downing & Locke, and the Lock, on Google Books.
Don't forget that there are or were some actual reference grammars besides the Biber that were published with accompanying exercise books (for learners of English if not their teachers), that may also be worth a look, e.g. the
Collins COBUILD English Grammar: Exercises, by Katy Shaw, was published (though way back in the early 1990s) for use with the *
Collins COBUILD English Grammar.
Remember also that a grammar dictionary or similar can be very useful generally. Chalker & Weiner's
Oxford Dictionary of English Grammar, and Trask's
Penguin Dictionary of English Grammar, are both inexpensive enough that they are well worth considering buying in addition to any comprehensive course and/or reference grammar; then, Michael Pearce's
Routledge Dictionary of English Language Studies is a very useful one-stop resource, particularly since its plentiful examples are all drawn from a variety of corpora and indicated as such throughout.
Most of these authors and their books have been mentioned if not quoted from before on the forums (International as well as Teacher) by at least me, so perhaps try searching for 'em with me as author if you want to see how they might've come in handy sometimes for ELT purposes.