what to do with used Veg beds?

I know this is a little naive of me but my onions are just about ready-well the leaves are starting to drop and turn,the onion are huge,ok,is it best to lift them out and just allow them to dry in the sun,then rub off any dirt or?I have been picking at them for a month now and using them as we need them.

Once the bed is empty,could I grow anything else in there this year?-and if so-what would would anyone suggest.This is our first real year at growing-very successful I must say,everything has gone really well so far!

I would really appreciate your input,the same again with my beetroots,the first crop is just about ready-these are very large too and would like to re use this bed if it is at all possible.

Everything is huge though I bought 6 tonnes of cow poop and this is what the base for all my raised beds are.topped with more organic smelly stuff,compost and some topsoil-all mixed in together.

The carrot head are 2 feet tall at the moment-they must love the mix

Here's a Link to a recent thread that may help
http://chat.allotment-garden.org/index.php?topic=60366.msg703129#msg703129