If a user tries to open a Workbook that is already open, then they normally get a message saying that the File is locked by a certain user and would you like to open the file in Read only mode. However, you can open a workbook in shared mode by following these steps. First open the file that you want to share, then once the workbook is open, go to the Tools menu and choose Share Workbook from the drop down menu. The Share Workbook dialog box will now appear. To enable sharing, you simply click once on the Allow Sharing check box, so that it has a tick. Once you do this other people will now be able to use your Excel workbook whilst you are working on it.
Thirdly, you can start use a spreadsheet program to schedule your time or organise all kinds of stuffs. You can use it to un-clutter you life by having different checklist on spreadsheets. After you learn the basics of spreadsheet programs, you can come up with more creative ways to use it in your daily life. You can even use a spreadsheet program to assist your weight loss plan. Use it to record your daily food intakes and you weight.