Register now to learn origami Saturday at the Ramsay Nature Center in west Alexandria. Origami is the ancient Japanese art of folding special colored paper into natural shapes, such as the form of a butterfly, fox or crane.

Participants must be 12 or older, and the fee is $12. The nature center is at 5700 Sanger Ave. To register, contact Nancy Moultrie or Joyce Zanone at 838-4831 or 838-4834.

For directions to the center, call a naturalist at 838-4829.

Handcrafts and baked goods are among the items that will be sold from 10 a.m. to 4 p.m. Saturday at the fall bazaar of the Ladies' Auxiliary to the Vienna Volunteer Fire Department.

Proceeds from the sale of items such as ceramics, miniatures, handmade chocolates and needlework and from a white elephant table will benefit the Fire Department.

Admission and lunch will be at no charge. The fire station is at 400 Center St. S. The Manassas Art Guild will hold its 14th Annual Christmas Mart featuring handmade Christmas and Hanukah gift ideas from 10 a.m. to 5 p.m. Saturday and Sunday at the National Guard Armory. Creations include paintings and original artwork as well as baskets, pottery, porcelain and china painting, dolls, and other crafts.

Admission is free, and food will be available. The armory is adjacent to the Prince William Fairgrounds on Rte. 234 South, Manassas. Choose from distinctive Icelandic outer wear and taste some of Iceland's delicacies at the Annual Icelandic Bazaar from 10 a.m. to 3 p.m. Saturday at St. Clements Episcopal Church in Alexandria.

In addition to offering a large selection of woolen garments and handmade goods, the bazaar will feature traditional Icelandic crepes, cakes and pylsa, a hot dog specially imported for the occasion. St. Clements is at North Quaker Lane and Dogwood Drive. Buy books for your child next week at the annual book fair of the Montessori School of Northern Virginia in Annandale.

A collection of more than 1,000 books will include parent handbooks and educational materials as well as books appropriate for children of preschool and elementary school ages. Fair hours are 7 to 9:30 p.m. Monday, 7:30 to 9 p.m. Tuesday, and 9 a.m. to noon Wednesday through Friday.

The school is at 6820 Pacific La. For more information, call 256-9577. The Arlington Arts Center is accepting solo exhibition proposals from artists living in Virginia, Maryland and the District through Nov. 21. Exhibit candidates must submit slides of their work for review in addition to the proposals. Six to nine artists will be chosen on the basis of proposals and follow-up studio visits to show their work at the center in 1989.

For more details, call 524-1494. Send slides and a proposal to Exhibition Committee, Arlington Arts Center, 3550 Wilson Blvd., Arlington, Va. 22201. Children's books, current and classic, are available today through Sunday at the Green Hedges School annual book fair in Vienna. Hours are 9 a.m. to 3 p.m. today through Saturday and 1 to 3 p.m. Sunday. At 1 p.m. Saturday, a professional storyteller will relate a selection of international folk tales.

On Sunday, the fair's staff will be on hand for grandparents who seek guidance in choosing appropriate children's books.

For more information, call Mrs. Stockton at 938-8323 or Mrs. Betz at 255-5463. Green Hedges School is at 415 Windover Ave.