One approach is to use Tools | Envelopes and Labels. On the Labels tab,
select a "label" definition for the sort of postcards that take up the
entire sheet (each one is 4.25" x 5.5"). Click on the New Document button to
get a sheet of the cards, which will be set up as a 2x2 table. You can, of
course, accomplish the same thing by setting up a table in an ordinary
document, but Word will drive you crazy with messages about your text being
outside the printable area; somehow (or at least sometimes) labels seem to
be immune to this.

--
Suzanne S. Barnhill
Microsoft MVP (Word)

Try using tables.. read the Help section in Word on how to create a table.