You can subscribe to the RSS feed for the whole ASC site, for the comments or on a section by section basis (using the topic rss links found in the right hand column of this page.)
Many modern browsers (Firefox, Safari, Internet Explorer) and email clients (Thunderbird, Mail, Outlook) will handle RSS feed subscriptions. There are also online solutions (like Google
Reader) as well as a host of desktop and mobile applications.
If you’re unfamiliar with RSS may we suggest reading the RSS wikipedia entry or watching the video below.