You'll have to register on their website to access the information, but it is free. You might also want to sign up with your local chapter since they put on the workshops. Some of the workshops are even free! They cover lots of topics including sales & marketing, business planning, finances, and a bunch of other stuff. If you want to learn how to write a business plan, this is the place to go.
And, if you need specific help, they also offer business counseling where you can meet with a business expert for an hour and get answers to questions specific to your business. And, it's free!