Hi, Denise! My husband and I have attended many business conventions at WDW over the years, and our plans usually go through the
WDW business meetings' area and/or the individual resort where the conference is being held. We usually receive several e-mails detailing various offers for the conference including specials on park tickets, entertainment options and dining. Therefore, I would encourage you to contact the representative(s) from your organization who booked the conference and ask for a specific area or Cast Member to contact about the specials to which I am referring. (Or, you can navigate the site I linked above to find your group.)
You should have received a confirmation number with your room booking, and if you book tickets associated with your accommodations, you should be eligible to add on a Disney Dining Plan. However, I would make sure to go through the business travel planners at WDW or with your organization to make sure you're getting the best deal possible. Usually, no discounts or current offers can touch the deals associated with attending a convention.
From experience, if the convention provides meals throughout the time you're there, I would think twice about purchasing a Disney Dining Plan. You are going to save time and money eating the convention meals -- plus, many times, it's better than an average convention's fare. Have a wonderful day, a great meeting and a magical trip!