There are many free chalkboards and fonts to download and use for your own uses, especially for any 'Back to School' events that you may have planned for your children's ministry.
You'll find some simple chalkboards, both dark and green, HERE. Remember, you can alter the appearance of these backgrounds with the online program, pixlr.com. It's an easy program and will enable you to add effects, vintage shades, stamps and text. Choose the Express version.
There are many differing font styles, too, to download and use. You'll find some HERE, Favourite FREE Chalkboard Fonts.
Another source of FREE chalkboard fonts can be found atyouthedesigner.com
Lisa Moorfield's site lists many creative scrapbook designs and fun fonts for your projects and you can find more chalkboard fonts HERE.
But you may wish for some lined, graph or note paper for your projects or to include in any Back to School designs. Generatedpaper.com has a large selection of different lined papers .. find themHERE.
Need some chalkboard powerpoint templates? Sure.. you'll find someHERE.
There are also sites with FREE school clipart that you might like to use. HERE