Hi Janice
Welcome to the Community!
If you put 'China' into the search function on the top right of the page, you will see loads of reviews, hints and tips from other JYers who have previously done the trip (including me and a detailed one from Bob Gray).
I did the tour in October 2014 and had a really great group (although I can't recommend my results from the dumpling making workshop....!). The currency you need is the Yuan, which you can order from your local post office or on line. (Make sure you don't get any old or torn notes because they won't be accepted). Credit cards are widely accepted, especially in the touristy areas (and at the silk and jade factories)
Other tips include taking wet wipes/sanitizer gel (you'll understand when you see the levels of pollution and the layer of dust on everything), cough sweets and, if you use inhalers for asthma, take double the quantity that you normally use.
Pack layers, really comfy shoes for walking (there's quite a lot of cobbles), lots of memory cards for your camera and have a super time!
All the best
Mandy