Montgomery County community calendar, Sept. 30-Oct. 7, 2010

USED BOOK SALE, books, CDs, videos and DVDs. Sponsored by Friends of the Library. 10 a.m.-1 p.m., Quince Orchard Library, 15831 Quince Orchard Rd., Gaithersburg. 240-777-0200.

MUSIC AND RHYTHMS OF LATIN AMERICA, Patricia Vergara and Cecilia Esquivel perform in Spanish and Portuguese. Part of the library's Hispanic Heritage Month programs. 10:30 a.m., Aspen Hill Library, 4407 Aspen Hill Rd., Rockville; 2 p.m., Germantown Library, 19840 Century Blvd. Free. 240-773-9410.

"RESCUE DAY" OPEN HOUSE, for all ages, activities and displays, demonstrations and tours of the station; firefighter hats for children. 11 a.m.-4 p.m., Bethesda-Chevy Chase Rescue Squad, 5020 Battery Lane, Bethesda. Free. 301-652-0077 or http://www.bccrs.org.

OKTOBERFEST, German crafts, games, music, food and a beer garden. Fireworks at dusk. 11 a.m., Ridge Road Park, 21155 Frederick Rd, Germantown. Admission, free. 301-340-1700 or http://www.germantownoktoberfest.org.

ABRAHAM LINCOLN HISTORY LECTURE, Brian Dirck, a professor of history at Anderson University, talks about Lincoln's career as a lawyer. 11 a.m., Sandy Spring Museum, 17901 Bentley Rd., Sandy Spring. Free. 301-774-0022.

FALL HARVEST FESTIVAL, music, antique farm equipment, gardening talks, tinsmith demonstrations, chestnut roasting, scarecrow making, pumpkin painting and more. 11 a.m.-6 p.m., Agricultural History Farm Park, 18400 Muncaster Rd., Derwood. $10 per vehicle. 301-924-4141 or http://www.aghistoryfarm.org.

POTOMAC COUNTRY HOUSE TOUR, including a contemporary home designed by David Jameson; the Avenel Farm estate; the River Falls Town Home; and more. With lunch and a vendor boutique. Noon-5 p.m., Saturday and Sunday, St. Francis Episcopal Church, 10033 River Rd. For information and prices, contact Carol Jarvis at 301-299-4296 or http://www.potomaccountryhousetour.org.

QI GONG CLASSES, for adults, easy-to-learn exercises that can be done using a chair for balance and stability, with directed meditation afterward. Noon, Margaret Schweinhaut Senior Center, 1000 Forest Glen Rd., Silver Spring. Free. 240-777-8085.

FALL GARDEN WALKS, meet at the Visitors Center. 2 p.m., Brookside Gardens, 1800 Glenallan Ave., Wheaton. 301-962-1400.

HISPANIC HERITAGE MONTH CONCERT, a performance by Ballet Folklorico Ritmos del Peru. 2 p.m., Marilyn J. Praisner Branch Library, 14910 Old Columbia Pike, Burtonsville. Free. 240-773-9460.

SINGLES DINNER AND MOVIE NIGHT, a support group for separated and divorced men and women. 5 p.m., fixed-price dinner, followed by a movie at the Regal Majestic Stadium 20. Sponsored by New Beginnings. Austin Grill, 919 Ellsworth Dr., Silver Spring. $30, includes soda, tip and movie ticket. Reservations required. 301-924-4101 or http://www.newbeginningsusa.org.

WOOTTON ROCKS 2, a benefit concert featuring Infinite Faze, Breaking Borders the Neon Rush. Proceeds will support high school arts programs. 7:30 p.m., Thomas S. Wootton High School, 2100 Wootton Pkwy., Rockville. $5. 301-943-0414.