We are using SharePoint Document Libraries for some projects now. The users are mapping the Document Library as a mapped drive. Users are also creating and deleting files. For the Projects site, the recycle bin settings are default:
Items in the Recycle Bin remain there until you decide to permanently delete them from your Web site, or until the items are permanently deleted after a set number of days, which is based on a schedule defined in Central Administration. When you delete an item from a Web site, the item is sent to the site’s Recycle Bin. If you click Recycle Bin on the Quick Launch, you can see all of the items that you’ve deleted from your site. You can either restore or delete the item from the Recycle Bin. When you delete an item from the Recycle Bin, the item is sent to the Site Collection Recycle Bin.
End-user deletes the Agenda document from a document library.
The document is moved to the Recycle Bin for the site, where people can restore it or delete it.
If the file is deleted from the site Recycle Bin, it is sent to the Site Collection Recycle Bin, where an administrator can restore it or delete it permanently.
It should be possible to restore user deleted items for up to 30 days. This requires Site Administrator privileges if it isn’t in the users recycle bin.