As Mark Hoffman wrote in his comment, there are good uncopyrighted maps of Patmos and the seven churches available.

BibleMapper / Bible Mapper Maps

This is a map that displays the location of Patmos and the seven churches mentioned in Revelation 2-3.The zip file contains 4 JPGs in color and in B/W with and without an inset.

Check out Dr. Carl Rasmussen’s magnificent web site: www.holylandphotos.org. Dr. Rasmussen provides very fine pictures, also of Patmos and the cities mentioned in Revelation. Go and take a look at Holy Land Photos. You will not be disappointed!

Here is an example from Dr. Carl Rasmussen’s Holy Land Photos: a photo of the remains of the Fortification Tower on Patmos. The fort was build about the third century B.C. It is significant that it was necessary to fortify this island.

Please, be sure to check Dr. Rasmussen’s Permission to Use page.

Wilson, Mark W. Charts on the Book of Revelation: Literary, Historical, and Theological Perspectives. Kregel Charts of the Bible and TheologyGrand Rapids, Michigan: Kregel Publications, 2007. 136 pp. RRP $14.95.

This book seems to be a helpful one if you need to get an overview quickly. You can take a look at its content at Kregel Books (see especially the 32 page pdf-file) or at Amazon.

It is recommended here by Dr. Alan S. Bandy at his Café Apocalypsis.

Update: See also Review by Jan G. van der Watt in Review of Biblical Literature