First see http://www.tradersbase.com/forum/technical-analysis/743-some-thoughts-volume-taken-context.html

Trendlines work the same as structure support in their use to see which side is winning the tug-o-war. A candle with a long wick bouncing off support with big volume could give insight that the bulls defended that level with vigor and probably ran stops to cause a spike they used to buy cheap. That same candle with no support causing the bounce would mean alot less in terms of a traders odds. This is why context is so important, the market 9/10 times won’t reverse in the middle of nowhere.

Now small/tight candles at support/resistance shows rotation and balance which I find as important as wicky candles. The more volume, the more rotation came in at that level. Everyone loves BIG candles, but super small candles with big volume are at least as important. If you see a big volume on a tight balanced candle get ready cause bets have been placed by both sides and only 1 can win that move in the end. Generally it’s a fade situation because if you’re at support and bears can’t drive it lower bulls stepped in to defend or vice versa at resistance.

Final thoughts for now…
BIG candles regardless of volume = momentum
Go with the flow till it retraces or balances/rotates.

Tight, high volume candles = balance nearing an end
Balance will give way to momentum soon, let the direction show itself then hop on the momo train.