In the past, I have used a USENET newsgroup to handle student questions. There is a problem with USENET newsgroups such as ucsc.class.cmps109, and that is that the ucsc news server does not distribute those news groups outside of the ucsc domain. This means that students trying to read the newsgroup from a computer using a commercial ISP cannot read them.
There is a solution. UCSC now has some online class management software that includes a discussion group mechanism. It requires a separate login and is accessible from anywhere, using a standard web browser.
Your WebCT login is the same as your cats/unix login: WebCT Login Page.