The Maryland Sales Tax Holiday will be Aug 14 ? 20. Below is the main website for the Tax Holiday, including an FAQ, and a direct link to the list of included items. If you read the fine print, only items whose retail price is under $100 is included, even if it is in the exempt category.
I plan on loading up on diapers that week!
Main website: http://www.marylandtaxes.com/ShopMD_2011/default.asp
List of Exempt Categories: http://www.marylandtaxes.com/ShopMD_2011/List-of-Taxable-Exempt-Items.pdf
Happy Shopping!