In learning about ferns or other tropical plants, 
there are a variety of bookshops or book 
dealers that we highly recommend.

Timber Press, Inc. is one of the largest and most dedicated plant book publishers.  They carry, 
not only books for those dealing in tropical plants, but they have a vast array of books dealing with temperate and hardy species.  Timber Press is where you will find Barbara Joe Hoshizaki's 
& Robbin Morran's Fern Grower's Manual.  Another general fern book is David L. Jones' Encyclopaedia of Ferns.

If you are looking for a specialized subject like staghorns, then nothing compares 
with Roy Vail's Platycerium Fern Hobbyist Handbook

Other fern books of great interest are:

Ferns for American Gardens, John Mickel

Ferns of The Tropics, Wee Yeow Chin

Ferns to Know and Grow, F. Gordon Foster

Ferns of Malaysia in Colour, A. G. Piggott

A Field Manual of the Ferns &
Fern-Allies of the United States & Canada, David Lellinger

The Ferns of Florida, Gil Nelson

Flora of Florida Volume 1 (Pteridophytes and Gymnosperms), 
Richard P. Wunderlin and Bruce Hansen

Flora of North America (Volume 2 (Pteridophytes and Gymnosperms), 
Flora of North America Editorial Committee

Ferns and Allied Plants (With Special Reference to Tropical America),
Rolla and Alice Tryon