Once you create your event and categories, you can post needs for items of for volunteers at any location at any time (within those categories). Volunteer needs can include One-Time needs with only one shift. Or you can post Open-Ended needs which have no set date (i.e. needed anytime). You can also post Recurring needs which have multiple regular occurrences on either a daily, weekly or monthly basis.
For each need, you can also select a View Status of Public (makes the need available to be seen by the Meet the Need network), Semi Private (show it only on your web site), or Members Only (restrict it to only be seen by your Approved Members; e.g. background checked individuals).