Usually you are entitled to a free credit report, just ask for it. When you do get it, though, read it cover to cover and try to have a list of questions about what you're not clear about concerning your report. That will save time in phoning your credit card company and asking questions or talking about your disputes.
Creditors and collection companies. You have to keep the lines of communication open between the people you owe money and the people who collect on their behalf. Doing so is a sign of openness and a willingness to work things out. Besides, the collection company will often take whatever you can give them. So don't close your doors and hide from them. That would only send the wrong signals and mar your credit status even more. Remember that you're aiming to repair it, not tarnish it even more.
Identity theft. Some people were victims of this. Someone bought using their names and they had to pay for the consequences. You have to protect vital personal information so that nobody goes around buying in your name. You have to dispute charges you didn't shoulder yourself. That's one reason you have to talk to the credit card companies about your free credit reports.
Laws and litigation. You must be aware of ways to legally protect your interests against unlawful practices of some credit card companies and their collection people. That way, you're prepared and informed and won't be forced to do things not in your better interests.
If you're trying to find a way to do the credit repair yourself, it's advised that you do it yourself and not rely on companies whose tips and efforts you will shell out money for. After all, you don't want to be scammed.
Remember that the very money you may be using to pay for their services you could already be trying to use to settle existing accounts and maxed our credit cards. It's best to do some research yourself.