1) You have to connect your iPad to the computer, select it under Devices in iTunes on the computer, go to the Apps Tab and scroll down to the File Sharing section.
iOS: About File Sharing
It's mostly a legacy method. There are better ways to save/copy your files to the computer.
2) All files are automatically saved, even if you don't close the document.
If you have an iCloud account, have enabled Documents and Data in iCloud settings, and enabled iCloud in Settings > Pages, all files will automatically be synced/saved to your iCloud storage. There are several nice benefits, and one drawback.
Benefits:
Sync with Pages and other iWorks apps on OS X (Macs) if you have one.
Syncs across all your iOS devices, if you enable it on them all.
Documents available for download/import/export at the icloud.com site via a computer browser.
Probably something else I'm not thinking of.
Drawback.
For whatever reason the iWorks apps (including Pages) all go looking for iCloud before displaying your documents. If the connection is slow or not there it can take a few seconds before the app decides to let you see and open a document. A minor annoyance, but I wish Apple would fix this.
Probably something else I'm not thinking of.
It is also possible to import/export your Pages documents to several cloud services; including DropBox and Box.com. It's not syncing, since documents must be manually transferred and will not normally overwrite the older versions.