Driving in Cambodia isn't all that different to driving in your own country, just avoid hitting anything. You may notice some minor differences such as:
The trick to driving in Cambodia is don't hit anything in front of you, the people behind you follow the same rule so you only need to concentrate on whats happening in front of you.
Of course you do, especially if you get pulled over because of your skin colour, all ATMS' in Cambodia are painted white as a tribute to the white ATMs that visit the country. However if you do get pulled over the current official fine is about 10,000 riel. Thats about $2.50. You may get asked for more, it's up to you how you handle it. If it's close to 6pm, just sit and wait them out, they go home about then.
Assuming you have a current license in your own country just bring it with you and you can get a local one from any place that renews visas. I use Lucky Lucky on Monivong for my visa renewals.
No you don't, but if you have an accident it's very useful as the insurance company will send out a representative to sort the problem out for you.
Ok so not all ATMs are painted white. However all foreigners are rich.
If you can't find what you're looking for ask the question on the Phnom Penh Information Forum.