So if it's the first time travelling to Cambodia and you don't know what to expect from a holiday in Cambodia, then you will be in for a surprise.
Travel in Cambodia is easy and safe. Most of the major roads are sealed and airconditioned busses operate between major destinations. A trip across the Tonle Sap lake and up the tributary river to Battambang is well worth the time. In the hot season water levels are low and it's best to take a speedboat as it won't get stuck on the banks of the rivers.
Travel from Siem Reap to Phnom Penh by boat is no longer a good option. In the wet season the lake is so vast you simply don't see anything but lake.The cost is $25 whereas a bus takes less time and is about $5.
Travelling south to Sihanoukville from Phnom Penh is best done by bus. The trip takes 4 to 5 hours depending on the bus company, the scenery is nice. I recommend you take a side visit to Kep and Kampot on your way back.
The people are friendly and helpful and many speak enough English to make your life easy.
Begging although present in the cities is non-existant in the provinces, the beggars are also don't pressure you much.
Remember if you give to one you'll get them all around you. If you buy a book you'll get all the book sellers.