first I'll give you some answers then I'll give you some friendly advice.
You can get whitepages listings from here
http://www.whitepages.com.au
If you mean is it legal, by asking if its okay, then as long as you are calling businesses then yes, it is legal. If you are calling households it gets a lot more complicated. There is good information here (
http://www.marketingminds.com.au/links/regulation.html) with links to even more info.
Again, if it's businesses you're calling, standard business hours is okay - Mon to Fri 9am to 5pm. If its households, you'll need to do some research at the above link and some others.
Now for the advice bit, telemarketing to households is a hard game. Most organisations simply play the numbers and know that for every 1000 households they call, they'll get say one lead. If your target market is households, there are better ways of reaching them.
My preference is often personalised direct mail, not the mass crap you may receive on occasion. There are a ton of copywriters on FlyingSolo that could help you create a well targeted letter for delivery into your target market.
I teach my clients to use a two step advertising model whereby in your letter you offer something that is low risk to the prospect (maybe say a free report, trial service etc) and if they respond to your low risk offer then you know you have a qualified lead. You then need a system in place to convert those leads into clients.
Good luck
Gary