Junior BookshelfMAKE ROOM FOR RAGS,by Laura Bannon; picturesby Vee Guthrie (HoughtonMifflin, $3). Danny loved Rags, the stray pup that his family reluctantly had given a home in their Texas farmhouse. But his attempts to teach Rags manners and make her useful were in vain. It was Rags herself who proved her worth by finding and taking under her protection two baby kids rejected by their mother. When the kids, grown as mischievous as Rags had ever been, were put in the pasture and Rags was threatened with banishment, a new job came along for her just in time, and everyone was happy.Lively pictures of Rags and the frolicsome kids add warm appeal to a simple little tale, by the late Laura Bannon. that children should love. (Age 6 to 9)LITO AND THE CLOWN, by Leo Poiiti (Sehribner. $3.25't. Lito was a sad little Mexican boy. A dog had frightened his kitten Paquka and chased her out of sight. Sow she was lost Then the carnival came to town, headed by Payco, a clown whostood so high on his wooden stilts that he towered overthe village's small houses. How the children loved him as he untangled their cities caught in trees and threw down balls found on rooftops And how Lito loved him when at last he rescued a terrified Paquiia from ahigh perch.Merry - go - rounds, ferrlswheels, puppet shows, and happy people — all the excitement aid gavety of a Mexican carnival comes alive in Politti s pictures, which attract with glowing colors and hold with fascinating detail. A beautiful picture book.HOW MANY ERS”YOU? by Marcie Hans: illustrated by Burt Goldblatt (Bobbs - Merrill, $2.75). Well. how many “ers” are you^ Are you a wriggler, a jiggler a giggler: A jumper, a talker, a■ fusser? A squeezer, a dribbler, a — well, whatever you are, you’re pretty sure to be in this amusing book, and you may not like the look of yourself so much. The rhythmic text and lively (tho not beautiful) drawings make it fun to read, and perhapsto see yourself as others seevou.