Although it's not required, some Agents like to MC the shows, and it gives a coherence and structure if you can pull it off. But when introducing people, don't read their bios -- just mention where they're from, one interesting thing about them and their name.

And in general, be nice. Some shows will go well, and some will be shit: that's part of touring. But if you can be welcoming, helpful and interested in the folks on tour it'll make a big difference. This is the first tour for most of them and they're often stressed, even if they don't show it. Some things you can do:

• Introduce them to the local act.
• Show them around if you can, or let them know where they can find food or interesting places nearby.
• They will have gotten in touch with you if they need a place to crash, and that doesn't necessarily need to be at your place: somewhere safe and free, is all. It's always good to know of a cheap hotel or hostel near the venue just as a backup plan, however.
• More and more people have food or allergy issues, and it's always nice to inquire as it relates to places to eat and sleep.