Well, if you set up periodic snapshot creation you can access them via the commandline in the .zfs subdirectory of the dataset you're snapshotting, or via CIFS on Windows on the "Previous Versions" tab of a file or directory's Properties dialog.
You can also set up replication in the GUI which allows you to move the snapshots to a backup system which will then have a mirror copy of the dataset, including the ability to "go back in time".
Restoration of a snapshot is an all or nothing deal on a dataset, so something you'll probably not be using much. It certainly won't help if you accidentally deleted a file and wanted to use a snapshot to get it back. In that case you simply copy it out of the snapshot back onto the live volume.
If you want to restore an entire dataset to a past snapshot you currently have to use the commandline.