[CuriouslyC]

Sales can mean a lot of different things. You need to identify your channel and type of sales before you can learn how to sell.

The only constant is knowing how to build rapport with your customer and make them feel like you understand their problem before pitching your solution. There are a lot of optimizations on top of that, processes for managing/tracking customers, etc, but if you can't connect with your customers and help them see why your product will save them time/money/etc you're dead in the water.