To access the survivor guide press start scroll down to handbook and press a. Then rb this will open up your survival guide this is an encyclopedia of the island when you find a new animal, person, enemy faction, location etc you will get a notification on the screen in game to pres the start button to read the info. From the survival guide if you press rb again you will access the collectables menu these count toward the 50 entries as the achievement popped for me on the third memory card I picked up from the safe house north east of Calvary point