For dim sum, Sheraton's Celestial Court Chinese Restaurant is a safe and fine choice. You may also want to try One Harbour Road in Grand Hyatt or Man Wah in Mandarin Oriental, if you enjoy a view of the Victoria Harbor. Please note that Man Wah only serves Dim Sum 11:30am to 3:00pm (Sat, Sun and Hong Kong Public Holidays) only.

Chinese Arts and Crafts is a good choice for silk items in Hong Kong. The closest location from Sheraton is at Star House next to the Star Ferry Pier. It is within walking distance (~10minutes) from Sheraton. Another highly famed, but a lot more expensive, place for fine silk items is Shanghai Tang. The main store is located in downtown Central in Pedder Building, just opposite the Landmark shopping mall. There is also a store located at Hong Kong International Airport, and one in The Peninsular Hotel across the street from the Sheraton.

Chinese Arts and Crafts:
http://www.crcretail.com/cac/index.asp?Lang=E

Shanghai Tang:
http://www.shanghai-tang.com/shanghaitang/index.jsp