Your first visit has to be to http://purplemartin.org/ as this web site is dedicated to the conservation of the Purple Martin. The site maintains printable documentation on to attract Martins as well as a catalog of useful purchases.

A book list is below…

Reference List
1. Allen, R. W. 1952. A study of the breeding biology of the Purple Martin (Progne subis). American Midland Naturalist
47(3):606-665.
2. Baicich, P. J. and C. J. Harrison. 1997. A guide to the nests, eggs, and nestling of North American birds. Second edition.
Academic Press, San Diego, California, USA.
3. Bent, A. C. 1942. Life histories of North American flycatchers, larks, swallows, and their allies. United States National
Museum Bulletin. 179:83-91.
4. Brown, C. R. 1997. Purple Martin. A. Poole and F. Gill, editors. The Birds of North America. No. 287. The American
Ornithologists' Union and The Academy of Natural Sciences of Philadelphia, Philadelphia, Pennsylvania, USA.
5. Dinsmore, J. J., K. H. Thomas, D. Koenig, C. P. Petersen, and M. D. Roosa. 1984. Iowa Birds. Iowa State University Press,
Ames, Iowa, USA.
6. Finlay, J. C. 1975. Nesting of Purple Martins in natural cavities and in man-made structures in Alberta. Canadian Field-
Naturalist 89(3):454-455.
7. Kendeigh, S. C. 1941. Birds of a prairie community. Condor 43(4):165-174.
8. Lund, T. 1977-1978. The Purple Martin in the western United Stares, with special reference to Oregon. Oregon Birds (3):5-10.
9. Macnamara, C. 1917. The Purple Martin. Ottawa Naturalist 31(5-6):49-55.
10. Rising, J. D. 1974. The status and faunal affinities of the summer birds of western Kansas. University of Kansas Science
Bulletin 50(8):347-388.
11. Stewart, R. E. 1975. Breeding birds of North Dakota. Harrison Smith, Lund Press, Minneapolis, Minnesota, USA.
12. Wolinski, R. A. 1995. Attracting martins: everything you need to know to attract purple martins to a new colony site. Bird
Watcher's Digest 17(4):80-84.
13. Ziegler, G. F., Jr. 1923. Notes on a Purple Martin colony. Auk 40:431-436.