I just finished a year in my first apartment. I dropped a fairly solid deal of cash (for me at least) and searched long and hard for various free things to fill it up with. It looked super well put together, was fairly decent quality, and I feel so much better now that most of it is gone. Don't buy high quality shit. You're probably going to find yourself making a bunch of mistakes and your tastes changing over time. You'll also find that you don't need it. Look at pawn shops and Goodwill for some incredible things. Used is fine in most instances. The one thing that I'm glad that I didn't get used was my couch (from Ikea). Don't get the bullshit print art from Hobby Lobby. Get their plastic frames and makes some original things with your friends or find some original print art. It'll cost you the same amount but you get to be original. http://www.theskidshop.bigcartel.com/products
Original paintings are pretty good too. I have two and they make a pretty big difference for empty spaces. One was a tapestry from peru ($30) and the other a painting from a traveling Israeli girl ($100). They look ballin and get lots of love. Try and buy according to what you need, not what you want. You'll appreciate this eventually, but may have to make your own mistakes by dropping cash on a Mad Men crib first.