Once you succeed in getting a credit card, you might be hungry to apply for many more cards. Not so fast. Having too much credit may have contributed to your debt problems in the first place.
Ideally, you should carry one or two bank credit cards, maybe one department store card, and one gasoline card. Creditors want to see that you can handle more than one credit account at a time. But use all of the cards only if you can pay the charges in full each month -- don't build up interest charges.
Creditors may frown on applicants who have too much open credit. So keeping many cards may mean that you'll be turned down for other credit -- perhaps credit you really need. And if your credit applications are turned down, your file will contain inquiries from the companies that rejected you. Your credit file will look like you were desperately trying to get credit, something creditors never like to see.
To learn how to get your finances under control, see Nolo's article Budgeting: How to Make a Budget. For detailed information on how to fix your credit situation quickly and easily, get Credit Repair, by Robin Leonard and John Lamb (Nolo).