Greetings, welcome! I was in your shoes not that long ago. The best thing to do is read some posts on this site and others regarding bow construction and design, topics involving arrows, and shooting styles. I bought "The Traditional Bowers Bible" and read it front to back. It has a ton of information, and it's sort of the Codex of Ultimate Wisdom for primitive bows.
I bought my first arrows at a chain store, but after that, I started making mine. You can buy flights or fletching and points online if you don't have anything nearby. For my arrows, so far, I've been using lightweight dowels, made of poplar or ramin. You can make your own with a squared piece of wood, shaped into a cylinder with a plane or draw-knife, if you want to be more traditional. My biggest secret to making my own arrows is super glue - it holds the blasted feathers on and keeps them moving while you get them secured with thread.
As for a new bow, you could try making your own. There's nothing better than having a functional bow that you made yourself. I used the tutorial on Poor Folk Bows (
http://poorfolkbows.com/oak.htm), although he uses fiberglass to back the bow, which is cheating (in a traditional sense). It worked great for me for my first bow. I've made eight bows now, and I love all of them. I gave my first one away last week to my best friend. He was blown away, it was a great feeling.
If you do decide to start this obsession, remember that you have to get used to failure, and treat it as an experience building exercise. I have eight SUCCESSFUL bows, and I have actually started twenty-six. Out of those, ten broke while I was making them, which was disappointing and sometimes painful.
Take a look around, and ask questions, we're all happy to help.
