Volume/number-safe/risky?

I hear much about volume being important. I Googled this: “What is good volume for a stock?” I got various results e.g. 1, 2, 3, 4, 5. All useful information but I’m looking for actual, specific number/numbers and only the Yahoo Answers site provided them. Here are a couple random examples of what I think might represent high and low: VALE, AUKNY

I realize the question may be too general but can someone provide me with a ballpark range e.g. 00000 to 00000000 etc.?

Its not always actual share volume that matters, but $$$ volume. Most stocks on the Nasdaq/NYSE are fine. A penny stock can have a hundred million shares hit the tape, but it may still only be a few thousand dollars worth. You want to make sure their is enough liquidity to get your dollars in/out when you want. If you're buying 100 shares you can trade pretty much everything and get out when you want. If you're buying 100,000 shares then you'll want to scale in and out according to the liquidity available and your trade plan. It will also depend on if you are buying for a 5 minute scalp or building a position to last a year.

A specific number can not be given here. Everyone has their personal preference that comes with experience and risk management. My overnight scan requirements are currently set at minimum 500,000 shares traded during previous session for stocks over $2. My live scans are based on $$$ flow and price action in the moment. If a typically lower volume stock all of a sudden has a large volume/liquidity increase my scan picks it up.