LA apartment rentals are REALLY expensive. I would advise going somewhere outside of the city/main areas - you'll pay for it in commute, but you'll be able to get a 2 bedroom for 1,400 to 1,500. You could try looking at
www.apartmentfinder.com - they have some nice complexes to look at. LA, in general, is expensive, so be prepared.
Things to see...there are so many! I love the Farmer's Market at Fairfax and 3rd - lots of great restaurants, and it backs up to The Grove, which is high-end retail and where you have a fighting chance at celebrity sightings. In the West Hollywood area, there are some great restaurants...for a rowdy atmosphere but AMAZING fajitas, try Marix, or if they are too busy/you're looking for something quiet, Basix is their cafe-type atmosphere restaurant right next door.
If you've never been to disneyland, save up and go. It sounds chintzy, and it is, but everyone needs to go, and 3 college-aged folks can have a lot of fun in Disneyland. Unleash your inner child!
Obviously, the beaches are always popular, and I'm of a firm mind that anyone who hasn't been to LA before should do all of the touristy things at least once - the Chinese Theater, the Walk of Fame...both pivotal, yet touristy, LA experiences.
Anything in particular you're looking for? Give me some categories and I can get you some places - I'm in LA once a month for business and have gotten to know it pretty well.