Should be an easy question...

Im setting up my laptop with ubuntu, its an older laptop so the battery sucks. Im looking for suggestions/recommendations on how I should setup my wifi. First I thought of just having everything load on boot, but if Im not at home (and not using it), wont having this on drain my battery faster? If this is true what would you recommend? maybe a simple script to run whenever Im at home and intend to use it?

Having WIFI on drains your battery faster, that is correct. The easiest solution is probably to get a new battery or to leave the laptop plugged in to the charger. Alternatively, you could just shut down the computer when you're not using it.
As to your question about a script, I think you could use
$/etc/init.d/networking stop|start
to shut down your network interfaces and start them again when you need them. Note that this is taken from memory, so it might not be entirely correct, as I haven't used ubuntu for some years.

- Findus