I have written two grammar books. Both are available (currently) for download. They are in a sense finished; I am also still updating and revising them.
Modern Powerful Punctuation and Grammar
This book attempts to explain modern punctuation and grammar. Actually, it should be a good source of things cutting edge (depending on your genre). In any case, a great source of information.
Sequential Phrase Grammar
This is a different grammar for writing. So, it can be very cutting edge. The book itself is also a unique look at grammar.