Some of the collectibles have changed from the original (aka switched to a new location), so I have made a new video for the Definitive Edition.
There are a total of 15 Energy Cells, 12 Life Cells, 33 Ability Cells, 12 Spirit Wells, and 9 Map Stones in the game. There are 45 Secret Areas.
Seasoned Explorer unlocks after finding 23 of them, and No Stone Unturned unlocks after finding all 45. Below is a video showing every Life/Energy/Ability cell in the game, as well as all Secret Areas, in chronological order according to the earliest you can obtain them. I suggest waiting until you have Stomp to go to Black Root Burrow as you need it to access the lower area.
You'll get this achievement when accessing the very first Secret Area near the start of the game.