You can learn about how to improve your sales skills on your own with various sales training products (CDs, books etc).
Some people prefer this to the classroom training events, sales coaching or group events.
I need to make it clear that there isn't a best sales system, just a best sales system for you.
This article explains more - Best Selling System or Best Sales Systems
Sales Training Products
Sales Training Books & Reports
There are more selling skills books on my Business Books Reviews Blog at:
Repeat Sales Training
The Sandler sales Institute take a different approach to sales improvement where you meet with other people keen to improve their sales skills and practice the techniques together.
Sales Training Blogs
On this blog, there are several collections of articles about various aspects of your sales skills.
If You Want To Improve Your Sales Skills, Take A Look At These Sales TrainersAri Galper - Brian Tracy - Chet Holmes - Dave Lakhani - Ian Brodie - Marcus Cauchi - Michael Port - Mitch Axelrod - Peter Thomson - Sandler Sales - Sean McPheat - Tony Alessandra
The Six Steps Profit Formula - Free Report (Click On Image)