I checked out some of the links listed above and found this one I thought was great. You can get free text book covers and free folders. They will print them in your schools colors along with your school logo or photo of your school. They are free of charge to primary & secondary schools anywhere in the US. You can check them out at www.ptquigley.com/products.html
I have been getting freebies from this site for the past few months. Tons of goodies including everything from free food to magazine subscriptions (I've got TV Guide 'till 2008, plus 9 others this month!). I'm sure that you'll find some things for you or your school:
There is a website called www.pgschoolprograms.com
where you can get free sample packs from puffs which is more for the 1st graders and you can also order Always for the 5th graders (boys and girls) the sample packs from always comes with a booklet about their changing body and a deodorant, all spice for boys and secret for the girls. You can also get the samples in spanish. I just ordered and it should come in august. I hope this helps.
At convention, State Farm had kits that you could order like - Earthquake preparedness, a prosocial approach to conflict, etc. They are binders with activities, posters for the classes, even videos- all for free (don't know why I didn't remember this until now)
contact your local State Farm insurance agent and ask them how to get them.
I also used a website for free bookmarks that was listed here and they were nice (the address is in the rooms, somewhere) It's been two months since I ordered them but they arrived just in time for the event that we wanted them for.
Does your area have a SAFE Kids chapter? I was able to get things like sun visors, camp chairs, down to sticky notes from them.
That's all I can think of for now.