After you have entered your tasking orders in Tasking Dashboard and Planet has started collecting imagery, you can download captures quite easily. After opening any tasking order, please open the tab 'Captures' and click on any capture you would like to download.
In the capture view, you can see a menu on the right side. On the bottom there is a link 'View in Explorer'.
Upon clicking it, you will be redirected to Planet Explorer. After logging in, you will immediately see the capture you are interested in and you can order it right away. To order, please click on 'Order Scenes' on the bottom of the page.
This is a manual way to order SkySat captures. Users can also order via Orders API - please see here.