Found here
Choose File -> Page Setup. You see the Page Setup dialog box.
Select the Sheet tab.
Select the Row and Column Headings check box.
To repeat rows, click the Return to Worksheet button next to the Rows to Repeat at Top text box; to repeat columns, click the Return to Worksheet button next to the Columns to Repeat at Left text box. The dialog box shrinks so that you can get a better look at your worksheet.
Select the row or column with the labels or names you need. You can select more than one row or column, as long as they’re next to each other.
Click the Return to Dialog Box button to enlarge the dialog box and see it again. The text box now lists a cell range address.
Repeat Steps 4 through 6 to select column names or row labels.
Click OK to close the Page Setup dialog box. Click the Print Preview button to make sure that row labels and column names are indeed repeating from page to page. To remove row labels and column names, return to the Sheet tab of the Page Setup dialog box and delete the cell references in the Rows to Repeat at Top text box and the Columns to Repeat at Left text box. You can also press Ctrl+F3 and delete Print_Titles in the Define Name dialog box.
for Adjusting the margins
Choose File -> Page Setup and, on the Margins tab of the Page Setup dialog box, change the size of the margins.
Click the Print Preview button (or choose File -> Print Preview) to switch to the Print Preview window. From there, you can drag the margin lines to adjust the size of margins (margin lines are the outermost lines). If you don’t see the margin lines, click the Margins button.