When a school, church, library, etc. asks you about your needs please tell them. Try to provide as much as you can for yourself, such as sound, but also determine if it would be better to use their existing sound. Usually a library has no sound. A school's sound is lousy. And a church has great sound.
Know how much space you need. Don't say, "I need the stage." Say, "I need a 10 by 10 foot space and I would prefer the stage. The stage may be used for storage and you may have asked the janitor to try to find room for a double garage worth of tables and desks, just so you can do a 45 minute assembly. I say, "I need a 10 by 10 foot space. (If you say 8 by 10 they don't know which direction is which, so think in squares.) I would prefer the stage if it is available. If the kids are seated on the floor everyone can still see."
Don't say "I need a mic." Say, "I need a wireless lapel or headset mic so I can have my hands free for magic tricks." I once went to a picnic and they said they would have a mic for me. They did. But no mic stand! Try doing a show with a mic stuck in your armpit or a little kid holding it up to your mouth. From then on if I'm driving I bring a mic and keep it in the car. The kicker is that they have never had me back. They assume I do that every time!
The library may not have much space for you, so plan to be flexible. Don't bring your spider backdrop and ask them where you can set it up if it obviously won't fit.
Meals: If they say, "What would you like to eat? We want to take you out for dinner afterward." Then don't say, "Anything is fine." Say, "I like anything but seafood." or "If you know a good Mexican restaurant, or buffet, etc. that would be wonderful." You could even say, "Anything without a drive thru."
Schools: How much time do you need? (Give them a five minute window. I need 40-45 minutes. I say this because the show is written for 45, but if they are 5 minutes late (usual) then I still like to end on time for recess, etc. If I said it's 45 minutes long and they come 8 minutes late and I stop after 38 minutes, they may feel cheated. Make sense? Give yourself a five minute window.
Table: Would you like a table? If so, let them know in advance.
If it is the first assembly of the year it is a good idea to have the principal praise the kids for how well they sat last year for assemblies and train the kindergartners on how to enjoy the assembly the most. If I start and I suddenly realize that this is the first assembly then I will take a couple of minutes and address it myself. "I have heard such wonderful things about how well you students listened at last year's assemblies. But I know some of you are seeing your very first assembly... Here is how they did it."
Introduction: The best introduction is one you can pre-tape. Or have the remote control puppet give it! That would be cool! Then you can add music to it and a radio dj voice, etc. But if you're as low tech as I am then have a card ready for the principal. Keep it about the topic, not about you.
"Our assembly today will be about Friendship Skills. How many like magic tricks? How many like puppets? How many know what ventriloquism is? Well, we're going to find out how to make and keep friends, from Mr. Tony Borders."
Water: Try to bring your own. Libraries often say, "Would you like some water? The correct response is, "That would be great!" or "No, thank you." Please don't say, "Could you get me a beer?"