Top of the page, over the tabs, click on 'Forums' (next to the globe icon). Scroll down to the Myst forums.
Or...you can get there from HERE.
I didn't mean to send you on a merry go around, nor did the others who answerd your question with links to the right place for mystquestions. It was all to help you on your way! I have played the original Myst, but as you posted your question on the Uru:Ages beyond Myst forum, I thought it better to redirect you to the Myst Forum. Most of the questions you will have will have an answer overthere. And I wouldn't be suprised if some of the other posters to your question can be found also overthere and willing to answer your question.
I hope you will find what you need and are then able to continue the journey through all the Myst related games.