Red,
Lots of advice here, most of it on design aspects which you may already have sorted.
I am just at the tail end of a rather large owner builder project and can give lots of advice if you are thinking of managing it yourself. there are so many ways to save money or get a better product for the same price.
Different story if with a building contract, but can be done.
As for your request for things to put in during construction, this is a small sample of mine:
1) data cabling to every room, cheap to do it now, expensive later.
2) wiring for security/and or CCTV system, including outside sensor lights
3) plumbing/power for an outdoor BBQ if you might need one down the track
4) in wall HDMI cables and extra noggings for wall mounts for that 80inch plasma you will buy in 5 years

5) same with speaker wire etc for your sound system, including outdoor speakers.
6) work out if you want a front door intercom/doorbell etc and allow cabling for it.
7) if your roof truss allows it, find a way to put in an access hatch and flooring in the ceiling to use as storage - with a power point and light.
8) we had the carpenter install a secret compartment (with false door) in the ensuite to store valuables.