As usual with all the books in the Take Control series, Take Control of Apple Mail was well worth reading. I haven’t used Apple Mail before and discovered several very nice features. Examples: inserting an iPhone photo into a message on Mac, and MailDrop for large attachments.
@Miraz That insert-photo-from-one-device-into-document-on-another-device sounds like true magic (I believe other apps can do it, too; IIRC I remember @danielpunkass talking about debugging it in MarsEdit on one Core Intuition I listened to earlier this year).