Railay viewpoint (on the east side) is a great spot to enjoy stunning views of the whole peninsula. However, it does involve a steep 30-minute climb through the jungle. You will come across boulders and jagged rocks but it's WORTH THE EFFORT. If you are planning on tackling this climb make sure you check the weather first. As it can become extremely dangerous on foot when it is wet. There are also many other activities to choose from. The day tours from Railay are a great chance to explore the local region. I found the 4 islands tour by speedboat to be my favourite. I got to see Koh Poda, Chicken Island, Tup Island and Phranang Cave Beach. This tour is great for snorkelling and seeing uninhabited islands. A day trip to the Phi Phi Islands is a must and a romantic sunset dinner cruise is not to be missed. Or if island hopping isn't your thing then I would suggest booking an elephant tour in Krabi. The elephants on my tour were treated well and looked after.
Railay has an abundance of accommodations to choose from like hostels, bungalows, medium-priced resorts, and a collection of luxury resorts. Check out the typical websites e.g. booking.com, trivago.com, and airbnb.com for great prices. But I would recommend staying at Bhu Nga Thani Resort & Spa. It is a bit pricey in terms of Thailand but by Western prices, it's quite reasonable. They have a fantastic buffet breakfast with everything you could want. Also, they have a spa, gym, pool, and best of all a bar by the pool. The Service here is great as staff will offer to take your luggage to a taxi boat if needed.
P.S. If this hasn't inspired you enough then I recommend watching the film The Beach, starring Leonardo Dicaprio.