When you're in charge of a classroom party, such as 100th's day... organize organize organize! Also, always make sure you know how many parents are coming in to help (if any... which I suggest you have a few- puts less stress on you!) Also, if you're doing your "party" in a centers or stations style, make sure you have something for those who finish early (and there's always at least one) to do while they wait to switch to the next center.
Our class celebrated 100th's day by making crowns, fruit-loop necklaces, a cookie, a super cute pizza with 100 toppings and gum-ball machine with 100 gum-balls (pictures to come), and a class book with things like "What will I look like in 100 years," "If I had $100 I would buy," "I would eat 100," and "My favorite thing about the 1st 100 days of school" pages. All of these things were very cute- but took a lot of prep!
For our class, it works very well using the ELMO image projector to complete pages (like in our 100 book) together slowly...instead of letting the kids go off on their own and work. This always seems to return higher quality work than if they work on their own! (Also works great for penmanship lessons!)
Happy Friday :)