Before Natasha hops a plane for Latveria Monday night, each Avenger has a folder on their pillow (wherever said pillow may be). Inside are thirteen one-page dossiers (such an auspicious number to begin with) that lay out the basics of each teammate, new and old. They're far from complete SHIELD files, but they give a brief overview of abilities and history (though not of secret identities). A note written in a sloppy scrawl reads 'Welcome to the Avengers' and is stuck to the pillow with one of these:
It doesn't do anything fun like talk to Jarvis.
Happy reading, kids.