Here are a few final items to get you on your way...
Write something in your user page
Let others know who you are, or at least what you are like and what interests you have. Just click on your name in the top right box, and start editing (now that you know how!).
If you want to ask a question about an article, or you have a concern or comment, you can put a note in the article's talk page. You do that by clicking the "discussion" tab at the top of the page. Don't worry if the link shows up in red; it's ok to create the talk page if it doesn't already exist.
When you post a new comment, put it at the bottom of the talk page. The exception is that if you're responding to someone else's remarks, put your comment below theirs. You can indent your comment by typing a colon (:) at the beginning of a line.
You should sign your comments by typing ~~~ for just your username, or ~~~~ for your username and a time signature. When you save the page, your signature will be inserted automatically. Most of us use time signatures because it makes following discussions much easier. For your convenience, there is a button at the top of the edit box with a signature icon which automatically inserts "--~~~~".
User talk pages
Every Monstropedia member has a user talk page, on which other members can leave messages. If someone has left you a message, you will see a note saying "You have new messages", with a link to your user talk page.
You can reply in either of two ways. One is to put a message on the user talk page of the person you're replying to. The other is to put your reply on your own talk page beneath the original message. Both are common on Wikipedia; however, be aware that replying on your own talk page runs the risk that your reply won't be seen, if the user doesn't look at your talk page again.
The Zen of Wiki
Being a Monstropedia editor is an exercise in emotional detachment. Always keep in mind that everything you add is open to editing, changing, mangling, and even deletion. This is the nature of a wiki, and if you take too much ownership of what you write here, you will end up angry or disappointed. However, if you can get into the groove of knowledge evolution as you watch articles take on a life of their own, then you can expect to be quite happy here.