Litchfield B&G is a beautiful resort. You're a little removed from all the action in Myrtle Beach, but it's not a bad drive. The beach at the resort is very nice and rarely crowded. If you enjoy walking the beach and don't mind a little distance, head north and you'll find yourself at Huntington Beach State Park. IMO, it's the best beach along the Grand Strand - no high rises and very few people.
Shelling in this area is not great. If you're really into shelling, think about taking Cap'n Rod's Lowcountry Tours boat ride out to North Island. He leaves from Georgetown and offers a great tour - http://www.lowcountrytours.com/ While you're there, Georgetown is a great place to wander around. It's the third oldest settlement in SC, and Front Street has a variety of small shops, restaurants and museums. The SC Maritime Museum is free and worth a quick stop. River Room is a great place to grab lunch or dinner.
Closer to Litchfield B&G, don't miss the Hammock Shops in Pawleys Island. They're a bunch of small eclectic shops spread around under old live oaks, and have been around forever. Brookgreen Gardens is a world-class sculpture garden just a mile or two north of the resort. It's a little pricey, but your ticket is good for 7 days. IMO, it qualifies as a "do not miss", particularly in the Spring.
Another "don't miss" is the MarshWalk in Murrells Inlet. It's a neat little boardwalk running between the Inlet and a row of restaurant/bars. Most of them will have live music every nite, and you can stroll the boardwalk and catch all the bands.
Food-wise, Quigley's is just across Hwy 17 from the resort and is a great casual spot with a very creative menu. Their blackened mahi tacos are the best fish tacos I've ever eaten. For very good seafood, I recommend Russell's in Murrells Inlet. Nothing fancy but their food is excellent. Russell will stop by your table to make sure you're satisfied.
For more ideas and info regarding the area around the resort, drop down to the Pawleys Island forum. Hope y'all have a great trip!
Edited: 14 September 2012, 14:38