A couple tips, while mentioned in the articles, I wanted to highlight. Dealing with the Credit Bureaus is definitely one of those things that still better done on paper, instead of electronically.
Get your credit reports through the mail, it's the best way to avoid signing up for services you don't need. A good idea to keep constant updates on your credit scores is to order 1 report every 4 months, cycling between the three credit bureaus. You can find the form to request your credit report here.
Also, send your requests by certified mail. You'll have proof of receipt, and a paper trail that will be useful if things go wrong.
Finally, make sure you keep your records up to date. It's very easy for something to be incorrectly reported, and it's even easier to dispute it if you have the records to prove your point. Save copies of your paid bills and make sure your records indicate what period the payment went towards. If keeping steady records isn't easy for you, give a service like mint.com a try. It won't do everything you should keep track of, but it taps right into your bank and credit card accounts and keeps good records for you. Plus, it has a ton of tools to help with financial planning and tax reporting.
If you do end up with a serious problem with the credit bureaus, you should consider hiring an attorney to help enforce your rights.