trading detail

I am a modest investor currently holding 9 diversified stocks including mog & meo. I keep track of prices etc on the ASX prices & reports page where I see the current price, movement, bid & ask, opening price , highest & lowest & turnover all I believe about 20 minutes delayed.
From time to time I see posts in various stocks where the author is able to quote the current bids & asks and the quantity to be bought or sold & most likely this information is actual & not delayed. My question is : How does one access this information? Your advice should be appreciated, thank you.