Scholastic has a range of resources and tools, strategies and ideas, student activities, books and other products available to teachers.
Teacher's Pet has a range of high quality, downloadable classroom displays.
Dafont has thousands of different fonts on offer and most are a free download.
Catholic Icing has a range of resources available for display in your classroom. It also has information about important dates in the Catholic calendar, information about the Sacraments and the liturgical year.
I get many of my display ideas from Twitter and Pinterest. Educators from all over the world post ideas up there everyday. Search 'classroom displays' to see for yourself.