Just make sure you follow the syllabus guidelines. Also, do one of the recognised "non-religions" (FYI-Wicca *is* a religion so dont do it).
Plus, if doing atheism, dont rely on students who "dont believe in God". They are not atheists, they are typical teenagers!!! (ie most have no idea what true atheism is and when questioned properly would fall more into either the agnostic bracket or just couldnt be stuffed bracket.......................
I dont know if I agree with the above statement either but to each their own..