Login to the frontend of the website and click on 'volunteer admin' in the user menu. You will see 4 links across the top of the page, right under the title 'Volunteer Opportunities':
Add Volunteer Opportunity?? |? Edit/Approve Volunteer Opportunities?? |? View Signups?? |? View Live Volunteer Page
Click on 'add volunteer opportunity' to add a volunteer opportunity. Fill out the form and click save.