I always thought doing hooks is a bit "old school" development practice :)

In order to hook your code on an existing object, you never have to define hooks or connect to existing hooks. We use standard inheritances practices between objects.

Suppose you have an object like this:

class sale_order(osv.osv):
  __name__='sale.order'
  def my_method(self, **args):
     # This method do something
     return True

If you want to hook to the my_method, you create an object that inherits from the sale.order object and extend it.

class sale_order(osv.osv):
  _inherit = 'sale.order'
  def my_method(self, **args):
     # do something before
     value = super(sale_order, self).my_method(self, **args)
     # do something after
     return value