The team memo should describe the (1) topic the team is working on; (2) audience & purpose of the document; (3) division of labor among team members; and (4) timeline for completing the work.

See chapter 14 to review memos if necessary.
The memo is “To:” me and from your entire team (so list the names of each team member in the “From:” line).
I suggest using headers within the body of the memo.
The timeline for completing the work shouldn’t simply list due dates for deliverables. It might consist of internal due dates and the process for completing each deliverable. (For the timeline, you could use list format, a table, or another format that makes sense.)
Have the memo proofread by as many team members as possible–don’t simply rely on one person.