It really depends on what you are cooking. In general, these types of noodles cook extremely quickly, so use your judgement ... 

Here's what I typically do: 

- Stir frying: "par cooking" - soak in hot water for a little bit, then drain and stir fry 

- In wraps, rolls, etc: "full cooking" - cook briefly in boiling water, then drain, rinse w/cool water and use 

- In soups: no cooking - simply drop into the soup (towards the end of cooking) 

Hope that helps!