This is my list. You can find them all on Amazon...
High
Ecology of the Planted Aquarium by Diana Walstad
Aquarium Plants by Christel Kasselmann
Planted Aquariums by Christel Kasselmann
Aquarium Plant Paradise by Takashi Amano
Nature Aquarium Volume 1 by Takashi Amano
Nature Aquarium World Volume 2 by Takashi Amano
Nature Aquarium World-Book 3 (Bk. 3) by Takashi Amano
Nature Aquarium World: How You Can Make A Most Beautiful Aquarium by Takashi Amano
Nature Aquarium: Complete Works 1985-2009 by Takashi Amano
Encyclopedia of Aquarium Plants by Peter Hiscock
Medium
Dr. Axelrod's Atlas of Freshwater Aquarium Fishes by Dr Harbert R. Axelrod
Baensch Aquarium Atlas Photo Index 1-5 (NEW REVISED THIRD EDITION 2007) by Hans A. Baensch, et al.
Baensch Aquarium Atlas, Vol. 4 (v. 4) by Hans A. Baensch, Ruediger Riehl
Baensch Aquarium Atlas, Vol. 3 (Third Revised Edition 2004) (v. 3) by Hans A. Baensch, Rudiger Riehl
Baensch Aquarium Atlas Vol. 1 (7th REVISED EDITION 2007) by Hans A. Baensch, Rudiger Riehl
Baensch Aquarium Atlas Vol. 2 (4th REVISED EDITION 2008) by Hans A. Baensch, Rudiger Riehl
Aquarium Designs Inspired by Nature by Peter Hiscock
Encyclopedia Of Exotic Tropical Fishes For Freshwater Aquariums by G. S. Axelrod
Low
Limnology, Third Edition: Lake and River Ecosystems by Robert G. Wetzel (Advanced Book)
Natural Aquarium by S. Yoshino, et al.
Aquarium Plants Manual (Complete Pet Owners Manuals) by Ines Scheurmann
Fishkeeper's Guide to Aquarium Plants: A Superbly Illustrated Guide to Growing Healthy ... by Barry James
Holger Windelov's Tropica Color Catalogue: Aquarium Plants by Holger Winelov
Aquarium Plants: The Practical Guide by Pabloo Tepoot, et al.
Fish Behavior in the Aquarium and in the Wild (Comstock books) by Stéphan Reebs
For beginners this site has an excellent guide at the top "Planted Tank Guide". I would also recommend the various forums, not just The Planted Tank. You have the Barr Report, Aquatic Plant Enthusiats, Aquatic Plant Central, AGA, IAPLC and to an extent MFK (not really for plants).