Won't this ruin my credit!

Yes, it sure will if you are not responsible and don't pay your bills. Your credit is one of the most valuable assets in your life. You cannot afford to not understand how it works in personal and business life. The credit score is always changing based on predictors of how much of a credit risk you are. If you understand how credit is derived it can be beaten. Not only has earning rewards and exercising my credit allowed me to leverage $100,000's of short term free capital it has increased my credit scores to levels I was never able to reach before. I've already put in the time and made all the mistakes so you don't have to.