Hi,
I am somewhat new to Arduino and I was hoping to build a medium/small sized quadcopter. I know a quadcopter is hard to build, so i have many questions.
Should i build a frame or buy a pre-made one?
What parts will I need (and maybe a description) and what is the best Arduino for this project?
What code to use?
Is there anything else I should know?
-Thanks 
Have you ever used an Arduino?
Do you have any experience with electronics in general?
Do you have any experience with programming?
Have you owned or operated a quad before?
If you answered no to any of these, you are in over your head. Use the search function of this forum and read some threads. Another place is Google. There are open source controllers out there, so take a look to see what actually goes into one.