How big should I let my squashes grow?

[Paulines7]

 :'( :'( :'( :'( :'( I haven't had any replies to my post about my yellow crookneck squashes.   See http://www.allotments4all.co.uk/joomla/smf/index.php/topic,22676.0.html

I don't know whether they are the right size to harvest and I must have about 20 of them on the plant.  I also have white pattison and again I don't know how big to let them grow.  I assume I can cut them up and roast them but do they have to ripen on a windowsill first?   :-\     Pleeeeease help!!

[Paulines7]

[plot51A]

Never grown them myself, so googled them.
Appears they are summer squash, and can be used interchangeably with courgettes. So no, you don't need to cure them - pick and use. As to size, probably best smaller than larger but its up to you - seems they are very prolific. Part of the courgette glut  ;D

HTH