I have here listed some of the resouces I use for conlanging. This list is far from complete, merely a starting point.
The Language Construction Kit
The kit offers a good introduction for inventing conlangs and a guide how to this yourself.
Zompist Boards
A very active online community of conlangers who can answer almost every question. I infrequently lurk around and use the search question to find material on the most obscure aspects of conlanging and linguistics.
Wikipedia
A good ressource for explanations to linguistic terms and for real language examples, e.g. Japanese Grammar
Verb Aspect
A very interesting article by Richard Harrison that influenced my own conlang considerable.