Like many other things in life, budgeting is a skill. Some people are better then others at managing their income and keeping in good standing in regards to their debts. Almost all of us have some sort of debt at any given time: a credit card bill, and outstanding loan, or a mortgage. By managing these debts properly, you will maintain a good credit rating which will allow you to continue to receive credit in the future. If you fail to make timely payments towards your loans - or worse, you let them go in default - you will find yourself stuck with a poor credit rating, which will rob you of many economic opportunities. In order engage in credit repair, you must slowly build your credit rating back up again. One thing that can help you do this is to seek the help of a credit counselor.
In general, credit counseling is performed by non-profit agencies, and is not to be confused with for-profit credit repair companies. The latter should be avoided. Credit repair companies have a reputation for being scams, especially those ones who advertise online. Even if it doesn't turn out to be a scam, it's likely that a credit repair company will do nothing that you can't do yourself: they'll direct you to obtain your credit report and challenge all negative items on it, and may even suggest you attempt illegal activities like getting a "new" credit rating thorough a different address.
In contrast, a credit counseling service will only provide advice, and in a context that precludes a profit motive. This is the best and most intelligent way to engage in credit repair. To deny that rebuilding your credit rating will be a long process requiring time and discipline is to do yourself a disservice, and a credit counselor will help you make the long term plans and decisions you need to in order to engage in effective credit repair.
Most good credit counseling organizations will provide you with advice and workshops, as well as educational materials. They will help you learn to both make and stick to a budget, which over the long term will be extremely beneficial to your credit rating. They will also be able to provide you with one-on-one counseling, so you can examine and learn to make good economic decisions based on your particular credit experience.
The problem with credit repair companies - and the reason you should be suspicious of them - is that they propose a quick, one size fits all solution. Anyone who claims they can quickly fix your credit without knowing anything about the situation is not being truthful. A credit councilor can be crucial in providing exactly the kind of particular attention that a credit repair company will avoid.
Most importantly, if you engage in credit repair by using a councilor, your solutions will be more long term, because you will be learning how to manage your budget more effectively, and making permanent changes to your spending habits. This is far preferable to paying a credit repair company that promises a quick solution that is of no educational value to you.

Brandon C. Hall maintains Free Info Blog which contains many articles and resources for credit repair as well as many other topics.