Squashes - when to stop them / pinch them out?

Hi all

On to brighter subjects after my tomato blight troubles yesterday!  

I'm growing four different types of squash:

Uchiki Kuri, Butternut (Hunter F1), Spaghetti, Serpente Di Sicilia (Cucuzzi)

They're all doing pretty well, with the Uchiki Kuri growing at a phenomenal rate.  One of them has around seven or eight small fruits.  What I wondered is:

- When do they need to be "stopped"/pinched out?  

- Is this necessary to help make the existing fruits ripen?

- Would the same apply to the other squashes, or is each squash dealt with differently?  

- Any other squash related tips? 

Many thanks as always

Max