The help desk is your communication center to your coworkers/members. It allows you to do two things: publish How-To's and respond to support issues.
The How-To's allow you to publish important information regarding your space and answers to FAQ's for your coworkers/members, ie. how to configure/use the printer.
You can manage and add How-To's under Manage > Help Desk > Add How-To.
You can upload documents and images as well as choose to make it 'Read-only' if you do not want your members to be able to comment on it.
Your coworkers can read the How-To's by clicking on them under the Help Desk link in their member portal.
If your coworkers/members have any problems (ie. the printer ran out of paper, trouble with a payment, etc.), coworkers/members can report them by clicking on the Report an Issue link in their member portal under Help Desk.
They can choose to make it private, so that only admins of the space can see it; or open so that other members can read reported issues. They can also attach documents or images if they wish.
After they have submitted the issue, you will be notified by email, see it posted on your dashboard and have an icon next to 'Help Desk' in the navigation.
Once you click on the issue under 'Open Issues', you can choose to comment and leave it open, or comment and close the issue. When you comment on an issue, everyone who has commented on it before will be notified again via email.
If you want to get information from your members when they sign-up, use Member Questions.