Acknowledgements and external links
If you want to learn Sindarin in greater depth, Real Elvish.net is definitely the place to go! I gained much of my additional knowledge from Bainwen, and still visit frequently.
This is the most complete dictionary to be found on the Internet (though it is missing some of the later Parda Eldalamberon 17 words)
I thoroughly recommend downloading Thorsten Renk's 'Pedin Edhellen', which can be found about halfway down the page, if you are serious about learning Sindarin.
This book (no. 17) is a valuable resource for anyone serious about learning more about Sindarin, and is still currently available to buy.
This is a random essay I came across one day and found it rather interesting and useful!