How to add a link
Read Whimsical Monkey's post about how to link.
Basically, you do the following:
Around the text you want to link, put <a> tags like so:
<a href="http://www.brynmawr.edu/">text that will be the link </a>
Be sure to include the full url, which can be obtained by selecting and copying everything in the address bar of your browser or by right-clicking on a link and choosing "Copy link location."
How to add a feed to the aggregator
First, you need to make sure you are at a site that has an RSS feed. Don't just include a link. An RSS feed is a special file that can be embedded into web sites or read by special aggregators or readers that can detect when the site has been updated. For example, on our site, the RSS feed for the main page is http://woi.brynmawr.edu/node/feed not just http://woi.brynmawr.edu/. The latter is simply the web address and won't be interpreted correctly by our aggregator.
Many sites, like ours, will indicate they have a feed by including the little orange xml icon (). Sometimes you have to look for it. Not all sites have them. An example of including the wrong feed is putting http://phillyist.com/ instead of http://www.phillyist.com/index.rdf.
Once you have the right link, you can copy it. Click on the aggregator link in the navigation. Choose the add feed tab. Give your feed a title and then paste the link/url into the url field. Choose a category, hit submit and you're done! From the list, you can also update the feeds although this will happen automatically anyway.
Some feeds, like atom.xml files, cannot be interpreted by our aggregator. There are ways around this, like using feedburner (http://feedburner.com) to convert the file and using the feed generated there in our aggregator.