Know how much you need.
As you get ready to launch your business, estimate how much money you will need to keep your business running for 12 to 18 months, or however long you believe it will take to give it a shot at success. Then figure out how much you can provide from your own stash—your savings, your family and friends, or cash flow from a current job. The difference between what you need and what you have is the amount you'll need to raise from other sources.
Download this worksheet to get a good idea.
Visit the Small Business Administration.
One of the first sources to explore would be the Small Business Administration, which is responsible for a huge amount of the funding that gets small American businesses off the ground. The SBA doesn't actually make loans itself. Instead, it offers financing at decent rates through normal lending channels like banks and credit unions. They're called SBA loans because the loans are guaranteed by the SBA. You can find more information on SBA loans on the SBA's website at sba.gov. In order to qualify for SBA or other loans, you'll need your business plan, as well as a history of your business experience.
Your personal credit history will factor in as well. Now's a good time to make sure your credit score is in tip-top shape.