I'm new to this endeavor myself. I started a couple of years ago - broke a lot of sticks and then laid off until recently when time opened up for me. I still broke a bunch more bows - learning all the time and reading as much as I could (recommend "The Bowyer's Bible, 3 volumes in paperback. Get volume one at least.)
Within the last month I have completed my first two bows that have held together. One is from Black Locust - 64" and 50lbs at 28". The second was finished two days ago - Osage Orange, 62" and about 45lbs at 26".
I had a cherry wood bow virtually done, 66" rawhide backed, tillered well (or so I thought), nice looking bow. Broke on the fourth shot - one limb just cracked in half.
Made a mistake somewhere.
Get yourself some wood and some hand tools. Make the thing from scratch. You'll learn more.
Pete