Bit Selection For Dado's? How to...?

Hi everyone.



I'm currently updating my router and looking at what size bits to use for Dado's amongst other things when using on MDF and Pine etc..



If we set this thread up for the "Standard" for those who are also looking then this will help more than just me.



If we want a good fit using 12mm stock in the Dado - what size is best 12mm or 12.5mm? Are there any "rules"?



Same again in 16mm and Impreial sized wood stock.





Please post here



Thanks everyone for your experiance and knowlege to share here.



"Man Caves NZ rock" ;)