When you first start up Maple under X, no worksheet is loaded. To load a worksheet you previously worked on, select the Open ... item from the File menu. A file selection dialog box with the title Load Session will appear. At the top of the dialog is a window labled Filter. The string that appears in this window determines where Maple looks for worksheets that can be loaded. When you first start up, this string looks for files ending in .ms in the directory you were in when you started Maple. Most likely, this will be your home directory. If you want Maple to look in a different directory, you can edit the string in the filter window and then click on the Filter button at the bottom of the dialog window.
In the middle of the file selection dialog are two windows. The one the left shows directories. If you want to look for files in one of the directories shown in this window, just double-click on its name in the list. The other window lists the files that match the filter string. To load one of these worksheets, select the name and then click on the Load button at the bottom of the dialog window. The dialog should disappear and your worksheet should be loaded into Maple.
Unless you deleted all of the Maple output regions before you saved
your worksheet, the output regions in the worksheet will appear to
contain the results they had when you saved it. However, the results
of the commands are not available to the Maple computational engine and
you must re-issue any commands the produce results you will need to
use in your current session. For example, suppose you defined a
function 
in your last session and then saved the worksheet. If
you want to use this function the next time you load your worksheet,
you will have to re-issue the command that defined this function. You
can do this simply by placing the cursor on the command defining
and pressing the return key.