Who is John Tolkien?

Personally, after reading the Hobbit and The Lord of the Rings in high school, I read his biography -- "J.R.R. Tolkien: A Biography" by Humphrey Carpenter (guest-edited by Tolkien himself). This book is still in print and available from most large bookstores or in online bookstores (Amazon, Barnes & Noble, etc.). You can request it by name or the ISBN number is: ISBN-13/EAN: 9780618057023; $14.00 or ISBN-10: 0618057021. A bookstore can look it up and order it from those. Also, you can do a google search on J.R.R. Tolkien and find a ton of info on him. A great deal of information can be gleaned from reading the book The Letters of J.R.R. Tolkien. They include correspondance from and to him mostly about the Middle Earth books, but include personal views and opinions.
He was born in Bloemfontein, South Africa but lived in England.
During his lifetime he lived in England. He passed away in 1973.