Are you going for BSB? And why are you staying in Edinburgh..? The roads around there are great, in paticular to the north and west. Edinburgh is a pain in the arse to navagate if you don't know it. It is expensive (although a good night out to be had). Unless you are looking for girls on your trip, I would suggest going to one of the towns around the track (say within 50 miles). B & B's all over. Nice wee pubs. Great roads. Nice people. Not expensive. Much better.
If you do go to Edinburgh, park near or on George Street. The hilton is ok, as is the Calton George. Expect to pay over £100 pppn. If its under that, it will be a dump. Very few city hotels have parking, and those that do will $$$. Anyway, bike crime is not a big issue, it's not London!
I now the city and the track well, I hope this helped and did not put you off.