Making your own kite? Try David Pelham's Kites to Make and Fly (Penguin Books), a bright and colorful book with clear instructions for assembling 10 kites of differing designs (included in the book). You'll learn about the relationships of wind speeds to the different designs and, as you put the kites together, better understand what makes kites fly. $14.95 at The Book Annex and Walden Books ... The Social Center, a psychosocial rehabilitation facility in Fairfax, has produced hand-screened notecards featuring Washington sites and flora. Sets of 10 cards sell for $4 at the center, 2810 Dorr Ave., Fairfax, or at 8220 Russell Rd., Alexandria. Call 698-1655 for a mail-order pamphlet ... Searching for wedding, bar/bat mitzvah or party invitations? Stationary, calling cards or announcements? Get a 20 percent discount for orders over $100 at The Paper Pear (933-4812 or 933-1905) in Kensington ... If you're tracing your genealogy, check the Prince George's County Memorial Library System's Maryland Room, at the Hyattsville branch library. You'll find more than 8,000 books, 40 drawers of pamphlets, clippings, maps, magazines and newspapers, as well as microfilm of early court records of the county, of the Maryland Gazette (1745-1839) and of census records and city directories. Materials can be used only in the Maryland Room. For more information, call 779-9330. TTY: 779-0040.