A5 is 8 tiles wide and 16 tiles high and are not autotiles. From memory, A1 is animated autotiles - water and waterfalls. If they are not named, use the descriptions above the slots to determine where they should go. If they are, be sure to only put them in the same-named slots (A1 tileset images should only go in the A1 slot). Usually they are named with A1-A5 or B-E as part of the name.
Then go into the Tilesets tab in the database, create a new tileset, and select your images to go into the appropriate slots.
They need to go into the img/tilesets folder (I'm assuming that's where you put them, but you didn't specifically say, so just pointing that out).
