In the game
You can touch or click the small paperdoll icon at the bottom-right of the game screen to bring up the full display.
On the Equipment tab, touching an item will select it to be your currently-usable item. Touching it again will put it away.
On the Wardrobe tab, each type (article) of clothing appears in its own section. Touch once to wear, again to remove.
For other players
If you open the Paperdoll display to full size, filling your display, a Changing Screen will appear in front of your character.
From the web
You can embed a “live” image of your paperdoll on your web page or blog with the Builder:Paperdoll API