javascript help

Hi,
  I have a lot of trouble finding information about using javascript
with ror, which is the reason for this second question on a similar
topic. Any way, right now I have a bunch of rhtml files with links in
them that you can navigate through. For example, one file has these
links under the finance category:

Tax
Bills
Banks
etc...

The user can click on Bills for example and he will get a view of more
links that fall under the category of Bills:

Non-Recurring Bills
Recurring Bills

Until the user gets to say a link for Gas and Electric Bills, which
would link to the list view for the GEBill model that I have. I should
mention that that these links are not part of any models that I've
created. They are just simple rhtml files with a bunch of <% link_to
..%> lines.

My problem is how can I make it so that the user can add a category. And
then within that new category, make more categories...

For example, the user should be able to add a link for Properties to the
first list of links. Then once the user clicks on that he can add more
links within the Properties.

Is this where prototype/script.aculo.us libraries come in? Does anybody
know of any good tutorials that could perhaps start me off on the right
track to solving this problem?

Thanks in advance.