The maps of the HS2 route are on the Department for Transport section of the Gov.uk website.
The detailed plans can be downloaded from the revised route of maps page. As well as the current precise line of the HS2 route, these plans show many of the other changes that will be needed as part of the HS2 scheme, such as changes to road layouts.
The Department for Transport are running two consultations, about compensation and about safeguarding. They have issues a sets of maps to go with each consultation.
Maps for the Compensation consultation
Maps for the Safeguarding consultation
Finally, HS2 Ltd have a google ‘overlay’ map, which shows the HS2 route superimposed on the exiting landscape. Please note that this does not show how roads and other existing features will be altered due to building HS2. We suggest viewing it in satellite mode as well as map mode.