Is it possible to edit song information when you get it into iTunes?

I can't afford to go out and buy a $25.00 gift card to iTunes to buy new songs constantly, so I use Ares to download my songs. The problem is, once I get them into iTunes, it won't say the album, artist, or anything, just the name of the song. I want to edit the information to where it will say the artist, album, have artwork, etc., but I don't know how. Is it possible? I just want it to look nicer on my iPod so when I'm searching for artists to listen to all of them don't say Ares.com.