"Lengthy" is the key word to note. Currently about 75 pages, and the contents do exhaustively list some explanations and solutions, mixed with an understandable amount of frustration and anger.
The short version is that Calendar and Contacts no longer sync when using the USB cable. Apple recommends using iCloud to facilitate syncing those particular items. The cause - there is a core OSsyncing component that was removed in Mavericks, well known and not a surprise to developers, not clearly shared with the user base.
For the many who need a solution other than the recommended iCloud (or any cloud) functionality, the primary options are backing down the OS from Mavericks to Mountain Lion, or to set up your own server to sync contacts and calendars, either as a separate CPU or by installing the server components onto your Mavericks machine. The revert to Mountain Lion gives USB sync back, while the Server solution moves the sync back to Local instead of Cloud, but does require WiFi or Lan instead of USB.
greg