Lingua Franca Nova:

Lingua Franca Nova homepage
Lingua Franca Nova Wiki
Lingua Franca Nova Disionario
Lingua Franca Nova Yahoo group
Lingua Franca Nova tutorial

Linguistics:

Español:

Introducción al Estudio del Lenguaje
Estructuras Básicas de las Lenguas
Fonética
Morfología
Desarrollo del Lenguaje en Niños

Los Orígenes del Lenguaje
Cambio y Evolución en el Lenguaje

English:

Introduction to the Study of Languages
Language Families of the World (maps)
Basic Language Structures
Phonetics
The Origin of the Alphabet
The Evolution of Alphabets
Morphology
Syntax
Componential Analysis
Semantics
Language Development in Children
The Origins of Language
The Evolution of Language
The Indo-European Family of Languages (maps and charts)
A Summary of European Pre-History
The Evolution of the Indo-European Language
The Evolution of English
The Dialects of English

Just for fun:

English Simplified Spelling
The Mars Alphabet