The Panasonic Lumix GH2 is a FANTASTIC camera for the price point. If you can afford it I definitely suggest going that route. Was I completely restarting my photo career now it is the camera I would be starting with. Unlike a higher end point of shoot it has the capability to grow with you. Also because of the 2x crop factor of the micro four thirds sensor you will effectively be able to zoom farther with it than on a DSLR with the same focal length lens. (Which for zoo photographer is very helpful)
It also doesn't lock you into any particular camera brand as there are many companies who support the Micro Four Thirds Standard so in the future you could switch to Sony, or Olympus, or Pentax, etc etc without having to completely repurchase all your lenses. Unlike say with a DSLR which generally have proprietary lens mounts.
But to help you out you can get a used Canon EOS Rebel XTi for under $300. It's an older camera, I still use it to this day (see my gallery)and when I upgrade I'm still going to keep it. It's not the best but for less than $300, you can't beat it especially when a decent point and shoot is about the same price.