How about a sports theme for your room. You can go to a party supply store and they have all kinds of sports related items. To make a bulletin board use the Title "Get Into the Game, Get Into School". Use napkins of different sports for a border, use paper plates as background for rules, subjects, etc. Be sure to include cheerleading and sports for girls. Hope this helps get you started.
I was a para this year and the teacher I worked with was 3rd - 5th intervention. She had a really simple and very cute theme of clouds and rainbows. The year before she had dogs and daisys the year before that. Next year she is going with strawberries and Strawberry Shortcake.
The older kids really enjoy the sports theme - and there are so many great posters to go along with it! You can include cheerleading and dance if you like, also. Put penants on the wall, sports' beanbags for reading corner (Walmart and other places have them), etc...
I am doing trains in my room next year to go along with "Train up a child..." and the Honorable Character system I use. I am seeing a lot of treasure themes around lately "Store up for yourselves treasures in heaven." Sports would be good with the older ones too. Have fun planning your new room.
I agree with the many suggestions for a sports theme. Please remember girls sports encompass much more than just cheerleading. Check out your local scrapbooking stores, teacher store, or go to carson-dellosa.com, or trend.com for some great resources and ideas.