In the three trips that I have made to Poland (always around the same time of year) I have been sweltering hot and down right freezing. So with that in mind you should approach packing clothes in a very strategic way.

First remember that you will have to carry what you pack and the luggage gets heavy even moving it around camp.  I suggest "layers' being the operating word. Casual clothes, jeans, sneakers, t-shirts etc will be fine most of the time.
A hoodie, or a sweat shirt is advisable if it gets chilly.
We will be attending church at Tomy Center and even though that is casual also I would strongly advise casual slacks and a button shirt for the guys and a medium to long skirt and casual blouse for the ladies. More on that at the retreat.
A ball cap or hat doesn't hurt if you have to get ready quickly or if there is an unexpected rainstorm.

Think of getting more than one "wear" out of the clothes that you take if possible. (hand wash in the sink if you need)

Other items to take:
  • Bible
  • Electric converter and European plug adapter (Wal-Mart or Radio Shack)
  • A small fan
  • Toiletries
  • An extra roll of Toilet Paper (we'll talk about it later)
  • A Passport carrying pouch
  • Passport (GET IT NOW IF YOU DON'T HAVE IT!)
  • About 100.00 spending money (Convert to Zloty here before you are in country...it's cheaper!)
  • Electronic equipment if you need. This stuff slows down check ins etc but you will have internet access (spotty)
  • Any supplies that you may need to lead, assist or may just be fun for the kids to do. (Frisbee, balloon animal stuff, Arts and Crafts, anything creative
      • AND A FLASHLIGHT!!! It gets dark in them thar woods!

This should get you started but feel free to ask questions along the way. Can't wait to be in Poland with you!