This is where I stayed for a few days while in Phnom Penh
http://www.rorysirishbar.com/
Rory and his lovely little Cambodian wife runs the place. The rooms are clean and have attached bathrooms. The reason I chose to stay there was b'cos I didn't want to wander about at night looking for people have drinks with while waiting for my travel companions to arrive. Must say I wasn't disappointed, met several very interesting people there . . . ask Rory about the retired Brit couple who were going to open a pub in Kampot.
Like Bonbon, I didn't feel very unsafe in PP.
Anyway, Rory's is right smack in the middle of town and you can walk to most of the attractions within half an hour north and south. The only time we hired a tuk tuk was to get to the Choeung Ek Memorial and The Killing Fields.
Sisowath Quay, the riverside promenade, is just around the corner from Rory's. There are lots of fabulous restaurants there. Absolutely must try Cambodian food especially the lobster soup (kinda like Thai tom yum) at the Pon Lok restaurant.
If you are on your own, steer clear of the seedy area along Street 51 at night. We saw a couple of has-been hippy types in their 60s or so making music and hanging out with the local hookers at the Walkabout Hotel.
http://www.walkabouthotel.com/
DV8 is also another one of those "oldest profession in the world" hotel.
The backpackers hostels are by the Boeng Kak lake. Lots of European students stay there. Clean rooms, very cheap and good food (had a meal there), about US$2 per bed and common toilet. But not advisable unless you're in a group of about 4 persons or more as the area is notorious for drugs and muggings at night.
A few useful phrases:
Cambodian greeting:
Sus die
Thank you very much:
Oar khoon cher run
The weather's v v hot and sun intense.
Don't forget a big hat, sun screen and buy bottled water.
Maybe face masks too as the earth roads can be very dusty. You'll see locals on motorbikes wearing them.
A fabulous restaurant in Siem Reap is at the Bopha Angkor
http://www.bopha-angkor.com/restaurant.html
As for abode, women are definitely very safe where we stayed
http://www.golden-banana.com/