With the Insignia and word "micro" to the right of the slot, label down will be correct. Insert the card slowly, should be smooth and easy. Most of the way in, it stops. Push it a bit and it springs back, then you know it is correct. Push it in flush and it will catch and stay. Once in, if you give another short push, it will release and spring partly back out.
The sd storage icon on the main screen only shows you the storage capacity of the card that is inserted in the camera not the st16 and only shows remaining storage when the H and camera are powered on and connected.
To access the Micro SD card, tap on the "Pad" at the bottom left corner of your screen, and then tap the 'apps' button. After that you should see all you apps including a Gallery. Tap on it and it will show what's in the Micro SD card. You don't have to have the 'H' turned on at all.
So this is a brand new SD card and there is nothing on it, it is formatted exfat. My understanding is that I have to mount it but after inserting the card and goint to settings-->storage--->mount nothing happens