When the court writes to you to tell you of the date for the directions hearing they'll also send you copies of your application form and any other necessary paperwork. You'll also be sent form CB3, which explains what you need to do with them (which includes sending the relevant paperwork to your ex).
To save you waiting for form CB3 though, here it is:
http://hmctsformfinder.justice.gov.uk/courtfinder/forms/cb003-eng.pdf
Ensure that you serve the forms (i.e. send them to your ex) as soon as possible. They'll show the time and date of the 'directions hearing', so that he can seek time off to attend. (As it's only a 'directions hearing', which will simply allocate the case to another time and date, he might choose not to attend but that's entirely up to him; as long as you've correctly served the papers you've got nothing to worry about).
Note that form CB3 only refers to '1st Class Post' but I strongly recommend using Royal Mail's 'Signed For' service (previously called 'Recorded Delivery') as well, so that your ex can't say that he never received the court papers