For many people, entering a new work environment for the first time can be a little scary. A new volunteer is not likely to know her fellow workers and may not be sure exactly what her job will entail or how well she'll be able to do it. Even if the job itself is clear enough, she may not be certain exactly what your expectations for performance are. All these are elements that can cause some unease in the beginning but are easily resolved, and it's up to the volunteer supervisor to resolve them. Because any work site with two or more people has a social element to it, it makes sense to ensure that a new person coming into that environment feels comfortable on a social level.
Providing a new volunteer with a mentor is an excellent way to introduce her to the library, its social structure and its working environment. A mentor can fill a volunteer in on the more human side of the library, explaining the administrative hierarchy and sharing information about the corporate culture - those values and service philosophies of the library that may be unwritten. While the mentor may not be the person doing the actual job training for the volunteer, it makes sense to provide for the new volunteer a person they feel comfortable asking questions of, and a person who will introduce them to their future co-workers.
If the first shift of a new volunteer is a short one, it may best be spent in getting a "back stage" tour of the library followed by an informal discussion of library philosophy. This is the perfect chance for the new volunteer to ask questions about the library and most importantly, to get a clear understanding of just how her work will contribute to library service as a whole.
The most important thing you can do on a volunteer's first day is make the workplace welcoming. For many volunteers, this volunteer job may be the first work experience since retirement - certainly for most it will be the first work experience at this library. The first day can be overwhelming and unsettling. You can increase the comfort level for a new volunteer by ensuring that she is made to feel as welcomed as she truly is and to see to it that she isn't hit with too many job requirements and tasks right away. By taking it slow and easy, and by helping the volunteer feel part of the team, you will likely increase the volunteer's enthusiasm for and commitment to the library.
After the new volunteer has been taken around and introduced, after getting a tour of the library along with a discussion of how different library departments work together to provide service, the volunteer can be taken to her own work site and shown how she will perform her job. At this point, a new volunteer may be introduced to the person who will handle the actual training -mentor and trainer need not necessarily be the same person. in fact, if the mentor is not responsible for training, you will have provided the volunteer with two contacts she feels comfortable with before the end of the first day!