Len Sweet's newest book, 11, is about the 11 'indispensable relationships' every believer needs in their life.
it's an excellent, excellent book - i've had the great privilege of reading it three times now, as i'd been asked by david cook publishers to prepare sermon outlines for each chapter of the text.
my outlines can be downloaded for free, with accompanying artwork, by clicking on the title of this post....
but - even if you don't download my stuff - you should really grab the book.
it's certainly one of his best