'What is an Aquatic Plant?
Article by Darin Gasperson from The Aquatic Greenhouse
Any comments? Recommend

[FAQ] Aquaria: Plants
Covers lighting, substrate heating, CO2, plant survival, a list of false aquatic plants, and many resources.
Any comments? Recommend

[The Krib] Aquatic Plants
[The Krib] Aquatic Plants
Any comments? Recommend

Aquarium Plant Library
Informative articles on all aspects of keeping aquarium plants
Any comments? Recommend

Aquariums!
including some good material on aquarium and aquatic plant related articles and subjects
Any comments? Recommend

Aquatic Plant FAQ
Information on all aspects of freshwater live plantkeeping. Also includes detailed information on lighting, algae and snails which may be useful to all aquarists
Any comments? Recommend

Center for Aquatic and Invasive Plants
the U. of Florida presents a large collection of links sorted into categories designed to be extremely helpful to anyone doing research or just curious about Aquatic, Wetland and Invasive plants
Any comments? Recommend

Plant Books
with comments and discussion (from the Krib site)
Any comments? Recommend

Plant Primer
Almost an FAQ on how to use plants in the aqaurium and get the best from them.
Any comments? Recommend

Plantnutx FAQ
I have been following Plantnutx for some time and will try to distill some of the useful knowledge into this FAQ. The names in brackets are the contributors of the answers
Any comments? Recommend

Plants in the Aquarium
by Reginald Dutta. General guide to their use in the aquarium with some helpful hints.
Any comments? Recommend

Robust Plants for the Dutch Aquarium
by Torsten Tiedtke. Most hobbyist first attempt at growing live plants will result in failure. Fortunately this doesn't have to be the case. There are many steps one can take to maximize the probability of success and I'll share those with you.
Any comments? Recommend

Water Plants 101
A basic Introduction to the physiology and ecology of aquatic plants
Any comments? Recommend