You'll need to be registered (but it's free and takes less than 2 minutes!). Then click on the Forum link in the system (it's at the very top on the right-hand side).
Type in your question (if it's an exam question, you can just tell us what year, paper and question number e.g. 2008 P1 Q3a), and we will help you with it.
We will answer any questions for Junior Cert or Leaving Cert.
Hope that helps in the run-up to exams!