Click File > Page Setup...
Select "Landscape". Optional: Empty the Header and Footer fields.
Click File > Print Preview...
More recent browsers allow Zooming. Play with zoom until it all fits nicely...
Click File > Print...
Click on "Pages" and enter "1". Click Print!
For Mozilla Firefox:
Click File > Page Setup...
Select "Landscape". Click "Shrink To Fit Page Width" Optional: Click the Margins & Header/Footer tab and empty the fields.
Click File > Print Preview...
More recent browsers allow Zooming. Play with zoom (try 70%) until it all fits nicely. Make sure it is set to Landscape. Click Close (or Print).
Click File > Print...
Click on "Pages" and enter "1" to "1". Click OK!