As Ms. Dawn says in the Preface to her book, legalism is contrary to the keeping of the Sabbath. The important thing is the keeping of the Sabbath for the health of one's relationship with God, and for one's own spiritual, physical, and emotional health.
I have found this book to be one of the most important things I've ever read: it offers practical ways for Christians (and others, if they care to borrow) to keep the Sabbath, which is helpful for those without a strong model to work from. The book is broken into four parts, of seven chapters each, so it can be read a chapter a day for four weeks, gently guiding the reader into a deeper understanding of and appreciation for the day of rest. It also focuses equally well on the negative (ceasing and resting from things) and positive (embracing and feasting) aspects of the Sabbath.
I am sorry that the previous reviewer of the book was unable to glean the many helpful and exciting ideas that I found, especially as both she and Ms. Dawn seem to have an equal respect for Abraham Joshua Heschel's book on the Sabbath (another book everyone should read). Contrary to her perception of it, Keeping the Sabbath Wholly is an holistic approach to Sabbath-keeping, entirely centered around God.