Unless you have stayed at a hotel before or it has come very highly recommend we suggest that you use an OTA (online travel agent).
We suggest Agoda, Booking(.com) or Expedia. A great reason for using any of these is an unknown fact and one that is not advertised. These OTA’s have accessible offices in Siem Reap and should something go wrong with a booking they are without doubt the most helpful people you could meet. In my experience as a hotelier and traveler this is very, very rare.
Dealing direct with a hotel will involve numerous emails and the potential of misunderstanding. Studies have shown it takes on average, 7 emails to confirm a direct booking. In addition to this hard work, hotels in SR and PP (and everywhere) often change owners and records are lost as are deposits.