Wayne Schiess’s legal-writing blog begins a post about summarizing your points with a very absolutist sentence: “Every legal document should begin with a summary of some kind.” Hear, hear!
He gives you pointers for doing so, with before-and-after examples illustrating how to present important information early, leave tedious details for later, and avoid abstraction. And since the title of the post includes “part 1,” you’ll want to follow his blog for the follow-up posts.