It's a great idea! Enotes does have a document section. We could theoretically publish an entire book there. However you can self-publish your book online. There are many options for doing so. Be careful though. There are also a lot of scams.
Here are some suggestions:
I'm afraid eNotes is not the forum for publishing a book; however, now is a great time for new authors to get published. Publishing a paper book is an expensive and risky proposition anymore, but the advent of e-readers has made publishing easier and less expensive. The first step for you, of course, is to determine which publisher or which kind of editor would be most interested in your book. Look at similar kinds of books (i.e., cookbooks, self-help books, young adult fiction, poetry) to find out which companies are publishing those texts. A quick look at their websites will tell you what they are looking for in terms of manuscript submissions. Best of luck to you!
You can contribute a document to eNotes. You get paid $1.00 for contributing a document to the site. I am sure that this is not what you are looking for though.
I would suggest going on-line and looking a publishing companies and sending books to them for contemplation. This is a very long process though. Many times a publishing house will want either an electronic copy or a hard copy mailed to their offices.
The easiest way to get started is looking on-line for companies currently accepting manuscripts. I would definitely start there.