First, give your Archive cabinet a name, so, in case you'll rez multiple cabinets, you will know what you will store in it. The cabinet can display its name as a hover text to identify it (you can choose the color in the menu).
The core organizing concept of Archive are drawers. You'll put everything you want to add to an Archive into a drawer. You'll give each drawer a name, the names are totally up to you.
Each drawer is linked to your Archive cabinet and has 1 land impact.
Once you've rezzed an new Archive inworld, create at least one drawer by touching the Ardchive cabinet and click "Add Drawer". You'll be prompted to give the drawer a name. Once you've entered a name, a drawer object is rezzed and linked to the Archive. You'll see a prompt that the drawer requests to be linked. Click "Yes" to complete the drawer creation process.
Repeat this for every drawer you want to add to your Archive.
Please note that the Archive will set a description automatically containing the Archive ID. Make sure you don't edit it. The Archive ID will ensure that the association between your Wardrobe items and the boxes in the Archive will remain.