Though there are many Tolkien Societies this one is the original started as an educational charity formed in 1969. In their own words:
The Tolkien Society is an international organisation registered in the U. K. as an educational charity, number 273809. Our aim is to encourage and further interest in the life and works of the late Professor J.R.R. Tolkien C.B.E., author of two of the most well-known and best-loved books of the late twentieth and early twenty-first centuries, The Hobbit and The Lord of the Rings. This site has information about JRR Tolkien (not, as often stated, JRR Tolkein), the books he wrote, his life, books others have written about him, our Society and its events, and a host of other items that you can find in the sections below. We also work with Tolkien Society Trading, which has a mail order list of books and many other items connected with Tolkien's works.
On their website you will find news of events, literature news, and articles on various topics related to Tolkien's work. You can also become a member of this society and receive many more amenities.
The Tolkien Society