Staffing situations vary from library to library based on a number of factors including population served, budget, and organizational structure. So who gets to staff programs? YALSA's guidelines lay out a number of considerations to take into account whenever making staff and volunteer assignments for a program, no matter our size or structure. Points 6.3 and 6.5 in particular consider the different roles that staff and volunteers take.
6.3: Consider which tasks are best suited to librarians and which are more suited to paraprofessionals, community partners and mentors, adult volunteers or Friends of the Library, and teen volunteers and participants.
With any program, someone needs to take the leadership role and accept responsibility for everything (the good and the bad) that comes of it. I find this is most often the person (usually a librarian) who pitches the program, and who believes in it enough to carry through with it. Whether hiring a presenter or relying on a crew of regular volunteers, the program leader needs to know (or find how to find) the answers to any question anyone may have about it from the time it first goes on the program schedule to three weeks afterward, when someone calls to ask when the next one will take place. The librarian leading a program is also most often the person charged with enforcing the rules as in, "Sorry, this a teen program for teens only."
Other staff may be recruited to handle specific aspects of a program because of their expertise in a certain subject area; for instance, having the graphic designer (who also happens to be huge Doctor Who fan) design crafts for a Doctor Who oarty. Adult volunteers and mentors may serve in similar roles. When a local Star Wars cosplayer learned of a multi-fandom fest we planned last fall, she offered to not only come in costume, but bring her collection of hand-made doll costumes and accessories for display.
Community partners can range from a business that donates pizza, to an after-school program that arranges transportation for their group to all attend together. We love community partners at my library, and are generally happy with any participation they are willing to commit to. Outside groups always have their own policies; a business may ask that we display coupons or flyers with their donated food. As long as their policies don't violate ours, we are happy to comply. The program leader is the one who needs to step in and explain, for instance, that we cannot post advertisements on our community bulletin board.
Teen volunteers step into a number of roles depending on the program, their maturity level and skill set; always under staff supervision. Most volunteers are tasked with set-up and clean-up. Some are more enthusiastic about these duties tha others. Every now and then you'll find a volunteer who enjoys running the sweeper over the carpet. Most teens love to help their peers during the program. If it's a craft program they may even provide one-on-one assistance to participants who need a little more help.
Teen Advisory Boards and other regular volunteers should get involved as much as possible during the planning stages. Are you offering prizes for a contest? Talk to the board members to find out what they think their peers would like. In the case of our Fandom Fest, a couple of Anime & Manga club members came up with their own ideas for an informal trivia contest, so I let them run with it. They put questions together, dug through their manga collections to compile prizes, and ran the contest as one component of the bigger program. I had them announce the trivia contest winners, and made sure to thank them publicly at the conclusion of the program.
6.5. When hosting programs led by outside presenters, consider ways to ensure that teens also develop positive relationships with library workers.
This point goes hand-in-hand with maintaining your role as program leader. Sometimes leading means showing up early to assist an outside presenter with set-up and making sure they have everything they need. You can use this as an opportunity to learn just enough about what the teens will be doing during the program to assist them later if/when they need it. You can greet the teens as they enter, take attendance, and show where to put their things. You can introduce the presenter, introducing yourself in the process. If you have a name tag or shirt to identify you as staff, then be sure to wear it. Then be an active presence throughout program. I try to carry a camera or smartphone with me to document the program. Mostly I find myself answering questions, like, "Where is the restroom?"
With many programs, maintenance and/or security staff will be in the room periodically. This is a great time to introduce them to the teens, and vice versa. The relationship between teens and these staff can be filled with friction; I think mainly because maintenance see teens as ones who make messes and break rules, and teens see maintenance as ones who scold them for natural behavior like eating and putting their feet up. It's during a program like the fandom fest where teens might learn that the maintenance and security are members of the same fandoms they are, and maintenance and security can see that teens are interested in making more than messes and noise.