Here's a really easy pattern

Here's a really easy, but cute, starter project that I designed a few years back for Lion Brand Yarns. They produced it as one of those freebie leaflets you see at the craft stores.

A Simple Starter Project --
Super-simple Beginner Backpack

This backpack is made all in garter stitch on size 10 needles using chunky yarn. It goes together quickly and looks great!

Materials: 2 skeins chunky yarn (such as Lion Brand "Jiffy"); size 10 needles; tapestry needle; homemade button (1") and bead (large enough hole to pull doubled drawstring cord thru) or purchased; 60 inches of knitted or purchased cording.

Backpack Base: Using size 10 needles, cast on 15 stitches. Knitting every row (garter stitch), work until you have 15 ridges on both sides (30 rows). Bind off.

Backpack Body: Cast on 25 stitches. Knitting every row, work 9 rows than place drawstring hole -- K2, yarn over (YO), K2tog. Work 9 more rows, work drawstring hole (make sure you're working on the same edge!). Continue in this way until you have 72 ridges done (144 rows) and 14 drawstring holes. Bind off.

Using big-eyed needle ("tapestry needle"), sew backpack body cast-on edge to cast-off edge. With drawstring holes at top, sew base to body tube -- ridge to ridge every 4 ridges, than 2 ridges from body to 5th ridge of base. Continue sewing tube to base by sewing to cast-on and cast-off edges of base just as you did the ridges -- until you have sewed tube all around base.

Backpack Flap: Using one of the size 10 needles, pick up 18 stitches (9 either side of back center seam) from top of body tube by inserting tip of needle from front to back into the edge stitch of the tube, wrap yarn around needle and "knit" stitch onto needle.

Garter stitch on 18 stitches for 5 ridges (10 rows) than begin to shape flap: k2 tog, work across to last 2, k2 tog -- every other row until 8 remain. Work buttonhole -- k2, k2tog, YO, k2tog, k2. Work 2 more rows on 7 stitches and bind off.

Make knitted cord by casting on 4 stitches and working until cord is 60" long -- or you can purchase a cord of similar color. Thread this cord, starting at the back center, in and out thru each drawstring hole. Thread both ends of drawstring thru large bead; tack ends of drawstring to two back corners of base. Sew button to front of backpack (pull drawstring and close flap -- mark where buttonhole falls and sew button there). Tuck in all loose ends and enjoy!