How to link one spreadsheet with another, so when entering data in one spreadsheet
This data affect the another ones?

Do you always want the data to flow ONE way? If so, you just need to create a cell-link from one sheet TO the other.

For two spreadsheets in the SAME directory on your hard drive:
In spreadsheet one, called Book1, enter a value in cell A1 on Sheet1. Save it.
In spreadsheet two, called Book2, enter the formula =[Book2.xls]Sheet1!$A$1 in any cell and save it.
Now close both books
Open just Book2. It should ask if you want update external data, say YES.
Any changes you make in Book1 will flow to Book2.

Now, if the sheets are NOT in the same directory, you need to list the full path in the [ ] like =[C:\Temp\Book1.xls]Sheet1!$A$1

Also, if you change the names of the sheets in the workbook, make sure you use the right formula... Sheet1 will change to whatever you named your sheet.

Please forgive me, I'm rather new at formulas... I did try your answer step by step and it didn't work. I'm sure I missed something somewhere but am unable to tell where. Not enough room here to post specifics.

You could try creating the "link" with the mouse instead.

1) Open both workbooks
2) In wb2 click on the cell you want to create the formula in
3) Press the = sign to start the formula
4) Now switch to wb1 and click on the cell you want to link to, and press ENTER
5) You will now be back in wb2 with the new formula created for you by Excel.
6) Repeat as needed.
7) Close wb1 and the formulas in wb2 will update to include the full path for you.