Document, Document, Document
It is essential that you keep meticulous records of the dispute process. By documenting everything, you protect your rights under the Fair Credit Reporting Act. You can prove that you appropriately notified the credit-reporting companies and gave them ample time to correct errors. If you need to bring a lawsuit against them, or if you want to publicize your plight,you'll need to be able to prove everything.
By keeping records and documenting everything, you not only build a legal case, you're also more likely to follow a systematic process that will yield results. You will know exactly what you have done, and what needs to be done next.
Keep copies of absolutely everything. Until your issue is resolved, you should consider anything related to the error extremely valuable information. Keep organized files of all of your disputes and communications with the credit-reporting companies. If possible (and legal in the relevant states), record any phone conversations on the matter. Keep track of how much time you spend, how much extra you have to pay because of any errors, and whether or not you have been denied credit or insurance.