Ask HN: Recommended resources for Small Business Owners and Entrepreneurs?

Think back to when you were getting started as an entrepreneur: What information or resources do you wish you had known about?

I'm building a resource library for Small Business Owners and Entrepreneurs who are writing their business plans.

Here's a few examples of the types of resources I'm looking for:

     * Fred Wilson's MBA Mondays  - A primer on business and business school.

     * A Smart Bear's Startup Lessons - Advice on pitching your business plan for an audience and the mistakes to avoid.

     * 5 Minute Guide to Cheap Startup Advertising - Primer on startup advertising resources

What resources do you wish you had been recommended as you got started as an entrepreneur?