Make an appointment today or tomorrow to donate blood Saturday through the American Legion 1987 Holiday Blood Drive at the Blood Donor Center of Arlington Hospital. Blood donations will be taken from 10 a.m. to 2 p.m. Call the Donor Center at 558-6434 or Robert G. Smith at 522-1390. Arlington Hospital is at 1701 N. George Mason Dr.

Take your family to make Christmas decorations, visit with Santa and enjoy holiday music tomorrow and Sunday at "Old-Fashioned Christmas," a holiday event at Colvin Run Mill Historic Site in Fairfax. Admission is $4 for adults and $2 for children ages 3 to 15. Hours are 7 to 9 p.m. tomorrow and 3 to 5 p.m. on Sunday. Colvin Run Mill is a Fairfax County Park Authority facility on Rte. 7 (Leesburg Pike), five miles west of Tysons Corner. For more information, call 759-2771.

This holiday season, buy an original gift for someone. Attend the Arlington Arts Center holiday open house and sale from 11 a.m. to 5 p.m. Sunday. Artists' studios will be open, refreshments will be served and visitors may choose from a selection of artwork created from various media. The center is at 3550 Wilson Blvd. Call 524-1494 for details.

The 15th Annual Community Holiday Bazaar and Craft Show of the Arlington County public schools will be held from 10 a.m. to 5 p.m. Saturday at Washington-Lee High School. The bazaar will feature 130 tables of holiday gifts, decorations and other items. Free baby-sitting will be available. The school is at 1300 N. Quincy St. For parking information or other specifics, call 527-7600.

If you are age 55 or older and need a source of income, consider registering with Senior Employment Resources. Supported by the Fairfax County Department of Manpower Services, Senior Employment Resources puts prospective employers in contact with senior citizens who are interested in resuming their careers or finding work. To be eligible, senior citizens must live in Fairfax, Loudoun or Prince William counties, or Falls Church or Fairfax cities. To make an appointment or for more information, call 750-1936.

Parents can arrange for their children to speak with Santa or Mrs. Claus on the telephone next week by mailing requests as soon as possible to the Alexandria Department of Recreation. Requests must include the child's name, age, telephone number, a specific time for the call to be placed and any additional information. Calls will be made from 6 to 8 p.m. Tuesday through Friday and 10 a.m. to 3 p.m. next Saturday. Write to the Department of Recreation, 1108 Jefferson St., Alexandria, Va. 22314.

Residents of the greater Falls Church area are encouraged to donate unwanted linens to local shelters for homeless families from now to Dec. 28 through the fourth annual "Shelter Tree" collection sponsored by the City of Falls Church. Surplus sheets, towels, washcloths and blankets will be collected in the main lobby of City Hall Monday through Friday between 8:30 a.m. and 5 p.m. City Hall is at 300 Park Ave. For more information, call the Department of Housing and Human Services at 241-5005.

Open your home this Christmas to an international student from George Mason University through the Seventh Annual Holiday Host Program. The program is intended to promote interaction and goodwill between U.S. families and visiting students from China, the Middle East, South America, Africa and other areas. Interested families must contact Kathy Dawson by Monday at 323-3574. George Mason University is at 4400 University Dr., Fairfax.