Sent debt verification Letters what next?

I got a copy of my credit report and noticed two debts listed that I do not think are mine, so I sent out two debt verification letters, and my question is do I wait until I hear from them, or do I send a copy of the credit report with the area highlighted that I am disputing, and send it along with a dispute letter to the three credit bureaus at the same time, or do I wait and see if I hear from the two companies who I have sent the debt verification letter? How do I go about doing this? MJ