Sihanoukville is named after the late king of Cambodia Sihanouk. The town itself is rather young; it was founded in the mid-1950s as the only deep-water seaport in Cambodia.
Since 2006 or so the town has seen an upsurge in tourists. Tourists will find a diversity of shops and restaurants. Life in Sihanoukville is very laid-back, the people are very hospitable, tourists are very much welcome and treated with Asian friendliness.
When coming to Cambodia don't forget its history. The country has to catch up with many things Western people are used to and take for granted.
If you rent a small motorbike traffic needs getting used to. It is as chaotic as in all Cambodian towns. Make sure you comply with traffic laws.