What happens to my stuff when my free trial ends?
Anything you create during the free trial period will be saved in your Workspace and can be accessed in full if you choose to subscribe. If you choose not to subscribe, your status will revert to that of a registered user at the end of the free trial, providing you with limited access to the site. This means you'll be able to see the items in your workspace but you won't be able to edit them or add new ones.
So if you'd like to obtain PDFs of those items and save them to your system, you'll want to download them before your free trial ends (you'll receive an email message letting you know when the free trial period is approaching expiration). Barring that, you can always export the tools as a registered user by accessing the Account tab and choosing the Export My Data option.