Sales-Tax-LogoRICHMOND, Va. (AP) _ Virginia is giving shoppers a break on buying back-to-school supplies.  Gov. Terry McAuliffe’s office says the annual back-to-school sales tax holiday will begin Friday and run through Sunday. During the three-day holiday, shoppers at retail stores statewide won’t have to pay sales tax on notebooks, pens, calculators, binders and other school supplies priced up to $20.  Shoes and most clothing items priced up to $100 also will be exempt from the sales tax.  The Department of Taxation has posted a list of eligible items and guidelines on its website, http://www.tax.virginia.gov.