From the introduction:
"There are worlds and whole universes far beyond that in which the kind reader currently resides. I know this for a fact as I am Uatu the Watcher and I am an observer of such realities. My main purview is what you know as the MARVEL UNIVERSE in all its diverse wonders."
"The changes wrought by time are more startling than initially conceivable, but all will be explained. I have seen this seemingly insignificant planet rife with Celestial activity far beyond any within this quadrant of the galaxy. I have witnessed the rise of Eternals and Deviants far more powerful than any others, and noticed with interest the visitations of the extraterrestrial Kree and their gestation of those who would later be called Inhumans. Human civilizations rose and fell, as did the Deviant civilization on Lemuria and the human on Atlantis in the second coming of the Celestials. This azure planet attained the great interest of the Watchers before its native human population discovered the most rudimentary forms of writing."
"All this I have observed and more, as I peered into alternate timelines, where the smallest event can change an entire reality. Throughout the history of the mortal heroes called Avengers, small events have become part of legend. The mere passage of the emerald behemoth known as the Hulk over a western railroad and his manipulation by Loki ultimately gave birth to the mightiest team of heroes on Earth—the Avengers! “A temper tantrum of the Sub-Mariner led to the rebirth of the living legend of Captain America! In the search for errors in his artificially intelligent robot, Henry Pym gave birth to the great danger called Ultron! All these small events led to greater legends and acts of heroism unparalleled. Read on, for here are the epics kept on those who respond to a call heard from Earth's core to the halls of Asgard: ‘AVENGERS ASSEMBLE!'"
"This is Captain America, and this is our basic orientation booklet for all new Avengers. Everything within this book is information to acclimate new members to their new role in their upcoming tours of duty with the team."
"Only after passing all the security and background checks do applicants receive a Communicard and this booklet to read. The first topic is the Avengers' place among the varied power groups on Earth, especially contacts and involvement with other superhuman crime-fighting groups. Next are the Charter and By-Laws. Read them carefully. The Chairbeing and fellow Avengers will answer any questions about operating procedures. This also booklet contains the current membership roster as well as some excerpts from the files of the active membership of the Avengers. The last piece of instructional material describes the various villains the Avengers have faced in the past. We Avengers have found a need to keep all our members updated on the tactics and tricks of villains we encounter, as they tend to return, often spoiling for a fight. With this information, newer members benefit from the wealth of experience the Avengers membership holds. Finally, we have included a personal piece from the only person to have stayed with the team from Day One, Edwin Jarvis. Though the membership is constantly changing and new and old Avengers come and go, this man is the only one of us who truly cannot be replaced."
"I wish good luck to all new Avengers, and may they find the steadfast camaraderie and loyalty that I have among fellow Avengers. This is a unique collection of beings, and one that all of us are proud to be a part of. Keep 'em Flying!"
"In the time since I was revived, there has been no greater collection of heroes and friends than the Avengers. Over the years, I have attempted to mold the Avengers into the most efficient superhuman peacekeeping force in the world. During these times, we have come into contact with many of Earth's other superhumans, whether as friend or foe. The following file is a list of the superhuman community in their particular groups and how the Avengers work with them or against them for the benefit of the entire planet. Captain America signing off."