While I agree that sales skills are important, my experience is you gain those skills on the field of battle. Reading a book or taking a "training" class, while helpful, do not build confidence or the experience necessary to have prior situations to fall back on to improve your skills.
I do think the law of large numbers is the best training ground for new salespeople.
There are some basic principles, that for me, with salespeople I have hired and trained over the years, have proven to be true.
Five basic sales principles
1. Salespeople don't need more "qualified" leads, they need more leads to "qualify". If it was easy to "get" qualified leads everyone one would have them.
2. Salespeople have to develop their own selling "style." I can't sell like anyone else and my guess is if anyone tried to sell like me they may not do well. I can talk to a salesperson about what they may do differently on the "next" call, however I'm not sure anyone can tell me or anyone else what they "should" do. I have seen hundreds of salespeople sell in a way that would never be successful for me, and that's ok. People who will buy from me buy from me because of the relationship we develop and those who don't buy from me may buy from someone they more closely align with.
3. People buy on emotion but they are moved to action by logic. Consequently, learning to ask questions is probably the best skill any salesperson can learn. Open-ended, closed-ended, tie-down, inverted tie-down, etc.
4. Learning the difference between a question and an objection helps to close sales. Questions "gather" information and objections "disclose" information, often when we have not closed a sale it is because we did not uncover the real objection, many times because we were too busy "selling" than helping our prospect "buy"!
5. Understand the purpose of questions, if I ask a prospect a question and I answer the question, whose answer is it, mine right? And if I ask a prospect a question and they answer the question then whose answer is it, theirs right?
The benefit of open-ended questions
Now, do you believe a prospect is more likely to believe a salesperson's answer or their own answer?
And if their answer "is" the solution then who are they more likely to believe?
An example: You are talking to a prospect and they have a limited benefit plan, say, "pays up to $800 for a brain scan." (Just an example).
You could explain all the pitfalls and financial risks of "up to $800″; you could talk about the cost of tests and procedures and learn if they want that financial risk. Or, you could ask open-ended questions, then use tie-down questions so their answer becomes the "solution."