Yep, those screws are the "eye" of "hooks and eyes".
Monarch- I don't think I ever held a drill before I built that cage. I bought all the tools and hardware, I had pretty much nothing to begin with. The only thing I had was a hammer that my dad bought me for my birthday. It took me a couple months since I was all anal about planning it but still changed the plans and made mistakes. And now that I have the tools, I actually use them. I built myself a swinging door out of plywood for my room (I technically live in a living room, so I only have a doorway--no door) and put up some curtain rods for my windows and stuff like that. I think starting with making shelves would be great and not too overwhelming!! KD pine is what most people use. It's inexpensive, popular and easy to work with. Usually you can look online and it'll specify whether it was kiln or heat dried or the wood will have a stamp that reads KD on it. You want untreated wood, also--nothing pressure treated for decks or anything outside. I don't know if there are any safe sealants or finishes, so I just avoided them.
It was a bit expensive, but no more than buying an FN and putting bass pans and wooden shelves in it. Whoever wants to build a cage, I'd say go as slow as you can within reason. You'll catch more mistakes and it will disperse the expenses so they are easier to deal with. And take advantage of free/minimal cost wood cutting at the store. I bought a cheap $6 hand saw and it does the job but takes forever with the wide boards for shelves. The wood for the framing was easier to cut on my own, since it was just 1"x2".
Thanks for all the compliments on the cage!!