What is a groundhog, anyway? Find out Sunday at Groundhog Celebration at Hidden Oaks Nature Center, 4030 Hummer Rd., Annandale. From 2 to 4 p.m., children and their parents can learn about the life of nature's fabled weather forecaster through stories, crafts and a slide show.

Call 941-1065 for more information.

Youths of ages 11 through 18 are invited to audition on Monday for Kinney and Company Youth Theatre's upcoming production of the musical "Annie."

Auditions will be held at Lee Center Auditorium, 1108 Jefferson St., Alexandria, from 4 to 6 p.m. Call 684-KIDS in advance to register. Membership fee is $60. Also ask about theater scholarships.

Fairfax County dog owners are required to purchase 1988 dog licenses by Monday for any dog that is at least six months old.

A license costs $10 for fertile dogs and $5 for infertile dogs. Duplicate tags are $1. Owners of more than two adult dogs must find out whether they need a kennel license from the County Zoning Administration before purchasing dog tags.

Licenses are available at the County Animal Shelter, 4500 West Ox Rd.; the County Office of Finance, 4080 Chain Bridge Rd., or at any of six county government centers. For more information, call 830-1103.

Come to a free lecture and panel discussion on "Blacks in the Military" at 7:30 p.m. Tuesday at Patrick Henry Library in Fairfax.

Speakers include William DeShields, retired army colonel and military historian, and Sylvia Taylor, teacher at the Louise Archer School in Vienna. Patrick Henry Library is at 101 Maple Ave. East, Vienna. Make a reservation by calling 938-0405.

Learn how to plan ahead at "Financial Survival," a free educational workshop that will focus on the financial planning needs of adult couples, from 9:30 to 11:30 a.m. Feb. 4 at the Fairfax County Financial Education Center, 5501 Backlick Rd., Suite 110, Springfield. Topics will include how to prepare for financial setbacks such as illness, death or divorce. Participants will learn the basics of organizing financial records, anticipating and planning for future needs, and identifying and using community resources. Register by calling 642-0815.

Business people in Prince William County are invited to attend "Tax Law Changes Affecting You and Your Business," a half-day seminar on Feb. 4 updating participants on changes since the 1986 Tax Reduction Act. The seminar, sponsored by the County Chamber of Commerce and led by area accountants, will give special emphasis to small businesses. Call 368-4813 today or tomorrow to reserve a spot in the seminar, 9 a.m. to 1 p.m. at Noble's Restaurant in Manassas. Cost is $20 and includes lunch.

Volunteer to answer and place telephone calls for the hearing impaired through Telecommunications Exchange for the Deaf Inc. at one of four Washington area offices. Volunteers are trained to operate a special typewriting machine that allows deaf persons to place and receive typewritten messages over the telephone. Tasks include making telephone calls for hearing-impaired persons and serving as a communications liaison between hearing persons and the hearing impaired. Office workers are also needed. Offices are located in Great Falls, Alexandria, Rockville and at Gallaudet University in the District. Call Rae Benedetto at 759-2993 or 759-4120.