Mentoring is the single most important aspect of selling that will determine success. If you want to have the credentials to land a job is sales, find a successful sales person and ask him for help. He may be able to provide you with a temporary job or some form of mentoring. The objective of having a mentor is to learn his dos and dont's. You can learn for a good sales person the concept of making a sell in the first and last 2 minutes of any conversation.
Once you begin the journey of sales, keep track of all success. Always get the name and number of the customers you have sold to. If you want to land an office job in sales, this will provide the proof of your worth. Also, ask the customer if they would provide a good reference upon receiving any calls about the transaction. You want to make sure that they will provide a positive reference. Remember, that your trail of sales provides the path of possibilities.
When you are looking to find a sales job, you should only sale what you believe in. One of the characteristic of a good sales person is to make the customer believe. How can you make someone believe if you don't; it is very hard. This is even true when applying to a sales job. The employer becomes your customer and you must make him believe in you and in your ability to sale their product. How to get a sale job is in your ability to sale yourself.