Please explain Equity Futures Contracts with a practical example. Also, can one close a futures contract the very next day and if so, by when will the amount be available for immediate use from that particular trade ?
Equity futures are contract that expire on a particular date and mimic the price action of underlying stock/index.
You can square of your futures position immediately after its created or whenever you want.
For details read here: http://zerodha.com/varsity/module/futures-trading/