In addition to there being an art book for Avengers: Endgame like all other MCU movies at some point long after the release of the movie, there will be a “Road to” book coming right before the April 26th opening.
Marvel did the same thing for Avengers: Infinity War last year, as the wait for the actual art book for that movie was so long to avoid spoilers; so the same thing will happen this year for Endgame on April 23rd. Ryan Meinerding revealed the cover for the art book on his Facebook page this morning:
April will be a huge month for Avengers: Endgame. Most of the merchandise will be hitting store shelves around the first of the month; and then tickets are expected to go on sale as well.