I am taking a trip to Bangkok, Thailand in August and planning to do a lot of shopping. I am not interested in the regular malls because I can find that in the United States. Can someone recommend me some markets around Bangkok with a variety of items? Also I just finished watching the travel channel they said Cha-Ta-Cha was the hugest market. Where is this place and am I hearing it correctly?

I am planning a trip to Thailand for a sabbatical/adventure/holiday and want to know how safe it is to do so alone.