Numbers are important no matter what business you're in or how big or small your business is. You've got to know where your money is going and what money is coming in to run a successful business. Therefore, it behooves you to learn the basic principles of accounting.
Learn the basic terms of accounting: debit, credit, account, asset, liability, equity, expense, revenue and profit.
Understand the purpose of accounting. It's not a magic fix for your problems, but without some basic accounting systems in place, you will never fully fix any problems in your business. Good accounting is a basic requirement that tells you what is happening in your business.
Find an online course for in-depth explanations of terms and principles of accounting.
Set aside 30 minutes each day, three days a week or a couple of hours on a weekend to study. Use that time to read the course material. Take notes as you read.
Review your notes for five to 10 minutes every day. When you've completed the online course, set aside a time to read through all your notes. Mark the principles that are still a little fuzzy, and go over that material again or ask someone who knows. Implement the accounting principles you've learned in your business. Actual application will help you understand and remember more than any other method.