> Hi all, is there any website where I can find papers and=20
> reports on the=20
> performance of squid (e.g. what is the optimal cache disk=20
> size..., max=20
> memory size?

The optimal cache size depends on the size of your use
community and their 'web behavior' : rule of thumb.
About one week of webtraffic generated could be taken
as an initial value for the cache size.

Once that is established check the SQUID FAQ on memory size
needed versus configured cache dirs and sizes.