Select (highlight) the files you wish to delete.
-> press the Delete key.
Click Yes or Cancel when asked to confirm that you wish to move the files to Trash.
If the Trash bin already contains files of the same name as those you are deleting, you will be warned and asked if you wish to overwrite the files.
Double click on the Trash icon on the desktop OR click Home and navigate to the Desktop folder in your home directory. From there navigate to Trash.
Select the files you wish to restore.
->.
Navigate to the folder in which you wish to restore the files.
->.
Restore a file immediately after deleting it
-> or press Ctrl-Z to undo the action.
With time Trash will accumulate hundreds of files. Rather than waste space, empty Trash on a regular basis.
Right click on the Trash icon on the desktop
OR
Navigate to the Desktop sub-directory of your home directory and right click on the Trash icon.
Click Empty Trash Bin in the context menu.