The first year we did a wishlist, we simply had a paragraph saying that we wanted to fill whatever wishes we could and then added a table to the bottom of the letter for their name, grade and what they wanted. This was posted in each of the two school's staff lounges.
In retrospect, it would have been easier and more efficient to have sent individual letters to each teacher.
If you have a specific dollar amount that is available for each classroom or if it's by grade level or an amount for the entire school, you should include that. Also, let them know if you are willing to purchase "consumables" like paper, pencils, crayons, etc. Our policy is to only purchase items that can be used many years or shared between classrooms.
We had teachers ask for everything from an encyclodia set to games for rainy day reccesses and everything in between. If they are using the same catalogs, it's easier for your group to oraganize the order and submit, paying with one check, versus each teacher ordering individually and then reimbursing them.
I think our letter went something like this:
Your PTA is granting your classroom wishlists. Below, you will find a chart for each of you to enter your name and what you would like the PTA to buy for your classroom. Dream big and list everything you would like. We may not be able to get all of it right now, but who knows in the future. The only thing we request is that you do not add consumables, such as paper or pencils to this list. We would like students in the years to come to benefit from the purchases also.
We also added a date for the list to be completed, giving it several weeks so that the teachers had time to look through catalogs, etc. When that date arrived, we took down the list, and any teachers not listed got a note in their mailbox giving them until the end of the next school day to leave a list of items in our box. Each of our 25 teachers had about $125 spent for purchases for their classroom.