Bike troubles...help!

Ok, I am the furtherest thing from a mechanic...so I desparately need some advice. My Ninja is giving me problems. The battery kept dying on me because I wasn't riding it enough, so I bought a battery tender. Once it was charged again and I got it to start, it's still not happy. It won't idle. I have to pull the choke down all the way to even get it started, and at idle it always wants to die. If I rev it some, it will hang around 3000 rpms for a few seconds and then die. If I let up on the choke any it dies immediately. So you see the common theme here...IT DIES! You fellows got any ideas why or what I need to look at to find out why?