There are many wonderful sources of how to make a bow from boards or from wood such as osage. This particular thread is quite helpful. Also, there are other threads on the Tradgang site that describe "how to" for building bamboo-backed bows, sinew-backed bows, yew bows, and many other types of bows. I hope this helps! The world of traditional archery is wide open to anyone with just a bit of patience.
http://tradgang.com//noncgi/ultimatebb.php?ubb=get_topic;f=2;t=000046
John
http://tradgang.com//noncgi/ultimatebb.php?ubb=get_topic;f=2;t=000046
John