Power supply understanding

[smeg up]

Hi,

I am building my own power supply as many others have. So far I think I have got all of the components and their values worked out (apart from the bleed resistor). Just stuck on the final 2 points so if someone could help me out that would be fantastic.

Here is a very crude drawing of what I have so far (didn't put values on or even correct symbols!)



My questions are:

1. How do I earth the circuit back to the earthing block?
2. Do I keep all components including the transformer isolated from the chassis and earth just from a single point?

Cheers

Mark