Well, I'd say anything that uses one separate partition for /home is a good enough idea. Anything besides that depends on how much trouble you're prepared to go through - Arch promotes a 100 Mb /boot partition formatted as EXT2, not sure about what the big players or other smallish fry say. I personally have a /, /home and swap scheme, and I have had no problem whatsoever so far. (Well... Besides bloody persistant configuration files doing untoward things when I install another distribution on top of it, but...
) I've also seen suggestions to keep a separate /usr partition, and one for /opt.
Can you explain what you mean about a data-partition, though? When I read that part of your post, I keep confusing it with a separate /home.
I think that's as clean and easy as you need. Perhaps not the most elegant, but this is what works for me
. Elaborate if you wish. I'm not going to give any advice on partition-size here - there will be more complete guides and suggestions elsewhere.
To do this, you'll more or less have to use a liveCD - at least, that'll be the least fuss, and the only way I've managed to easily do things to my partitions. (Linux doesn't like you working over a mounted filesystem, see.) Keep note of which partition you mean to use for which mount-point!
Once logged in on the LiveCD, the only indication you'll get is device/partition-number and filesystem. Then you just... open up GParted/Partition Manager and work your magic. There is, however, nothing safe about this procedure - backups are wise.