The second book is out, it's called 'Can I Be Better Than Before?". It's during the events of 'Captain America: Winter Soldier'. There is 4 books to this series.

1 Book) The Avengers

2 Book) Captain America: The Winter Soldier

3 Book) The Avengers: Age of Ultron

4 Book) Captain America: Civil War

Sorry for not telling you guys about this like....a long time ago. :P