Once you have clicked on the "Stock List" button, you will see a list of your current live stock, similar to below:
To select/deselect a stock record for ad, you can right click the row, it should turn green when selected.
You can edit the fields by clicking once directly into the column.
Double clicking on a stock record will open the Stock Edit screen.
The tick box on the far left is for you to highlight multiple stock, to be archived/selected/deleted, using the Stock List Footer Menu
You can sort each of the columns by clicking the heading.
If you hover over the column heading, click the down arrow, you can add/remove columns:
Simply tick/untick the columns as needed and this will update immediately.