As soon as you started working with a spreadsheet, immediately save it to make sure that you will not loose any data.
Make sure to give the file a name that will clearly and accurately represent what is located inside. If you name a file with some abbreviation or code with a thought that you will always remember what it means, you are mistaken. First of all, you will forget the meaning with time. Secondly, another person will not understand it.
The best way to name your file is to give it a short version of the title in the spreadsheet. For example, my file name will be "BookDivIncomeStatement as of 12.31.06.xls" for an Income Statement of a Division for twelve months ended December 31, 2006.
If you will have revisions of data in the file, you should save all the copies (if you have to) with clear identification of the revision number and a date. Always identify your final version.
It is good practice to save your final version in Adobe Acrobat format that will preserve your final version from any changes.
"BookDiv_2007_SalesForecast ver.1 @11.30.06.xls"
"BookDiv_2007_SalesForecast ver.2 @12.31.06.xls"
It is a good idea to include a version and a date when the file was modified or created. It would give vital reference to everyone when keeping changes between various versions.
Also, it is always a good idea to include the file path:
1. Either in the footer (in the file menu go to View/Header and Footer/Footer/Insert file name and path)
2. Or right under the title (by typing formula =cell("filename"))