BarberFobic1992,
I a level 2 NFAA (National Field Archery Assoc) instructor. I am not bragging, rather just stating my credentials. My wife and I teach trad. archery at the local rec. center and I am a volunteer trad. instructor at our local archery club. Some advice:
www.stickbow.com - navigate to the leatherwall forum and post your questions. You will get more advice than you can ever use. You can even post a video of yourself shooting and get some critiques of your form.
Do not over bow. I am a scrawny guy too, with a long draw length. Don't get involved in the ego of how much weight you can pull with a trad. bow. You are going to shoot a lot of arrows to start. Starting with a light bow, 25 - 30 lbs. will help you develop form and build up your muscles. Your draw length will change as you develop your skills and you can try a bunch of different trad bows and see what you like before you buy your good bow.
A recurve is more forgiving than a longbow.
Buying American is great. There are a lot of very talented American bowyers out there. However, it is very difficult to find an American built beginners trad. bow. The imports are all pretty decent starter bows. Be careful with e-bay. There is a good classified section at stickbow.com
Get a set of arrows that are matched to your bow. This is an art unto itself.
Do not pull with your arms and shoulders. Good form makes use of your back, especially the scapular muscles on the arm that draws the string. You are trying to get the scapula on the arm that pulls the string to touch the scapula on the other side.
A slingshot is good practice until you get your bow. It is also good practice for the times that you cannot shoot your bow. Everything is identical except gripping the pouch.
If you have a local archery shop with trad equipment, hang out and learn from the experienced archers.
Have fun and shoot safe