Salsa allows you to create exports of your supporter list by Segments, or in its entirety. To make an export, first log into Salsa and find the Supporters section along the left-hand side (1):
Once you've clicked on Supporters, you'll be taken to the Manage Exports page. By default, you'll be on the Supporters tab. Click the Manage Exports tab (2), and you'll be taken to the Exports section. You'll see that you have some options available to you. Once you've built up a few exports, you'll see that you have a search field that will allow you to quickly find the particular export by name. You can navigate through the pages of exports quickly, once you have multiple pages worth of exports to browse. Since this is probably your first export, click the "+ Create an Export" (3).
This will take you to a screen where you will be ready to create your first export.