Does anyone has a good idea of how to get from Jakarta to Bali, how far is Jakarta from Bali anyways?

It's convenient to go straight to Bali by airplane from Jakarta. Bali is about 1,000 km east from Jakarta.
However if you want to travel inland Java and be a backpacker, its depends on how much time available to spend, here's some suggestions:

If you don't have much times: straight go to Bali from Jakarta
If you have quite some times to spend: Jakarta-Yogyakarta-Bali
If you have A LOT of time to spend: Jakarta-Bandung-Yogyakarta-Borobudur-Surabaya-Bromo-Bali

You can go traveling between this cities by plane or train (buy Executive class train ticket, its more convenient), traveling by bus is not recomended, its not convenient, but if you want to be adventurous and meet real Indonesian people, go ahead.

Why don't you ask tangawizi. I'm sure she can gave you good suggestions. I heard she had backpaking across Indonesia some times ago.