This is an excerpt from Dollar Scholar, the Money newsletter where senior writer Julia Glum teaches you the modern money lessons you NEED to know. Don't miss the next issue! Sign up at money.com/subscribe and...

Learn what happens to your credit score after you apply for new credit.

Here's how many credit cards you should own, according to experts.

Wrangling with security deposits, cosigners and pay stubs can get taxing — especially if you have a low credit score.

Here's how you can protect yourself.

"Credit repair" services claim to boost your score overnight. Do they actually work?