The Highway Code is available in book shops and is fully illustrated.
It can be downloaded, in Greek only, here.
There is also a PowerPoint presentation, also in Greek, which can be downloaded here.
Some of it is similar to the UK Highway Code but with the updates to the UK version, there are now some major differences.
Many of the differences between the two Codes are outlined within this site.
The Highway Code can be used to assist a prosecution.