Hi,
The Cambridge Double Star Atlas is the definitive one, but it is not free (from US$11 used on Amazon) so we go to the Mag 7 Star Atlas on Cloudy Nights
http://www.cloudynights.com/item.php?item_id=1052
Since there are so many doubles and multiples, this is available in 20 pdf files, indexed by RA and Dec, making it easy to pick out the chart you want. Double stars appear on the charts with a short horizontal line, where they have separation > 0.5 sec, and a secondary of mag 11 or brighter.
Note that if you use these charts elsewhere in a publication, they are copyrighted even though free.
Cheers