Coding for hover text, Links, hyperlink

In marketpress how do I add a link or hover text to my products description…

In particular one that will appear when I hover over items in the description.

An example would be on my site one of the things I am selling is Called the Sage Snacker. It list all the products included in it. I want to be able to hover over each item on the list and it give me a ingredient list or link to an ingredient list.