Add Extra Step (Custom Data Form) before Complete order

[Mostafa Hashem]

I need to create an extra step before the order being created 

All i have to do that when the customer click on checkout moves to another form to collect more data 

and once this form validated and data saved  will be move to checkout step

the customer must fill this form data  to continue the process to create the order 

i have started by using hooks but i didn't find any one used for pre checkout and how will move to a module to handle this

what is the best solution to create this form and move forward next