What do I need to do add a link section, and maybe put in a twitter widget? Like Stickfodder has.

You would need to edit the html of the comic page to add those things... you're using the basic template, so the code is available in your comic's control panel (under one of the tabs/buttons...). However you'll either need to code in a table or area of some sort, and each link (to do the links) or get the twitter box code that you can copy/paste into the html (to do the twitter box). In either case you'll need to know enough about html, just a little familiarity, to get it in the spot you want and to display the way you want. If you have an html editor like dreamweaver that can help, if you copy the code DD gives you and paste it into dreamweaver, you can play around a bit and see what different things look like.

Well, how about the code for a basic table? I don't remember much HTML.

Google is a valuable resource for this stuff.
I found a page to help you here:
http://www.yourhtmlsource.com/tables/basictables.html