Is college really neccessary to start your own business

It's not necessary depending on what type of business it is. Often times having a degree validates your company.
Regardless, you need a very well defined business plan established. This business plan should answer these basic questions:

How much money do I want to make after all costs are incurred?
What my cost of doing business?
How long will it take for me to be profitable?
Do I have enough reserve funds to get me to that point?
How do I scale my business?
How do I take time off?
What if my costs increase, how do I account for that?
What's my opportunity cost for establishing this business ie: working for a company or borrowing money to start the business.

The Good
You will make important friends and valuable contacts. A large part of your success in business will depend on who you know, and who knows you. College provides you with an opportunity to cross paths with potentially thousands of people.
You will gain a depth of knowledge. While you can learn just about anything on your own, college can speed up the process, making it faster and easier to learn the skills you’ll need throughout your lifetime.
A college degree could open doors for you. Potential business partners, investors, and clients will look at your education and experience, and may use it as a determining factor when deciding whether or not to do business with you.
College is fun. There is nothing quite like the experience of college. Your time in college will be among the most memorable days of your life, and you may regret missing out later in life.

The Bad
College is Expensive
Time-Commitment
Non-relevant courses

Before making the decision, try asking yourself the following questions:

Do you already know what you want to do with your life? Have you already begun building your company?
What is your learning style? Do you learn best by being “taught”, or by teaching yourself?