3 broken laptops, how recover data and/or fix?

I have 3 macs all in various states. Earliest one is an iBook G3 (clamshell) (300MHz, with a 6GB HD), it's missing the battery, has a dead pixel line, but otherwise fine. I'm thinking of upgrading it as best I can so that my son can have something that I don't mind him mashing about on.

Next one is an iBook (12in, 600MHz, 16V RAM), I currently have another unsolved question about it on here, but basically it was working if plugged in, now there's nothing (won't start, seems absolutely dead).

The third is a Powerbook G4 (12in, 1.33GHz), which took a tumble. I'm thinking the logic board on this one is busted, but everything else should work. Would like to recover the data if possible, but don't know how.

My only operating mac (besides a 2GB iPod Nano) is another Powerbook G4 (15in, 1.5 GHz)

Any suggestions on how to combine any of the parts, or to turn one into an external HD?

And if not, best to strip them and sell parts separately or as a whole?