River Song's diary

River Song kept a diary of her adventures with the Doctor.

It was a present from the Doctor after she saved his life, a few hours after regenerating and attempting (and almost succeding) in killing him. The cover is blue and resembled the exterior of the Doctor's TARDIS.

Since the diary was written from River's point of view, she didn't let the Doctor read it, jokingly saying "Spoilers" and often putting her finger on her lips. The book acted as an indicator of where the Doctor was in his personal timeline, for whenever River Song met him, she would name events she had had with the Doctor to see if that Doctor had experienced them yet.

History
River's diary was a gift from the Eleventh Doctor. (DW: Let's Kill Hitler)

After returning from a trip with the Eleventh Doctor for her birthday, River met Rory at the Stormcage Containment Facility. There, she checked her diary to be sure of where the Doctor was in his timeline. (DW: A Good Man Goes to War)

In 2011, River and an 1103-year-old version of the Eleventh Doctor compared diaries. At this point in his timestream, the Doctor had a similar diary. (DW: The Impossible Astronaut)

In the 52nd century, in Stormcage, River wrote in her diary before taking a phone call from Winston Churchill and escaping. (DW: The Pandorica Opens)

After the eleventh incarnation of the Doctor reset the universe, River gave Amy Pond her diary as a wedding present, though all its pages were empty. This helped Amy remember the Doctor and bring him back. Later, the Doctor returned the diary to River, telling her that the writing had all returned, but that he had not looked at it. (DW: The Big Bang)

After the crash of the Byzantium, Amy asked River what her diary was, to which the Eleventh Doctor, who had yet to experience events recounted in it, told her to stay away from it. (DW: The Time of Angels)

When the Tenth Doctor met River Song for the first time from his perspective, she attempted to "do diaries" with him, naming events which they had attended together. He did not know who she was. When the Doctor tried to read the diary, River stopped him and told him that, by his own rules, he was not allowed to read it. (DW: Silence in the Library) After the events in the Library and River's death, the Doctor left the diary in the biography section of the Library. He and Donna Noble considered reading it to find out their futures, specifically Donna's (given River's reaction to her identity), but chose not to. (DW: Forest of the Dead)

Recorded adventures

 * The aftermath of Demon's Run. (DW: A Good Man Goes to War)
 * A trip with the Eleventh Doctor to Easter Island. (DW: The Impossible Astronaut)
 * An encounter with Jim the Fish. (DW: The Impossible Astronaut)
 * Rebooting the universe. (DW: The Big Bang)
 * The crash of the Byzantium. (DW: Silence in the Library)
 * A picnic at Asgard. (DW: Silence in the Library)
 * An adventure in the Bone Meadows. (DW: The Time of Angels)