You can take a look at the photos I took in the last 10 years in Siem Reap. I am there every year for the Angkor Photo festival and personal works for travel magazines....
http://www.flickr.com/photos/jeffreyyap/sets/72157594318178115/
http://www.flickr.com/photos/jeffreyyap/sets/72157594321635716/
I would recommend staying at one of the guest house I always stay when i am there.
You can see the info about the guesthouse at:
www.peaceofangkor.com
The guesthouse owner, Dave Perkes, is a great photographer himself. hepersonally trained all his staff, drivers and tour guides to be able to bring photographers around for phototrips. All his staff etc knows where to bring you for what type of photos at what time of the day and without making you a poor man at the end of the trip.
Give Dave an email or call before you go & he can sort out all yr stuff for u, pick up from airport, land travel arrangement, accommodations, tour guides, Archeological Park entry pass, food, drinks, itinerary etc.
Ask for his best tour guide by the name of Taa (Elit Chor). This guys knows hellavu the Angkor area & a lot of the newly uncovered temples complexes that are yet opened to the tourists.
Just a simple advice, dun ever get a taxi from the airport. You will be charged sky high price as the Transport Council there is the biggest mafia who will cream off u. Arrange it through the guest house. The same driver will be the one that ferry you from the day you arrive at the airport til the day u leave at the airport.
Hope that helps.