Hi,
I am no expert got I got really good advice from one yesterday. The credit expert said that profile an of 800+ credit score typically have the same look: 1 mortgage, 1-2 installment loans(car,student,etc), and 2-3 revolving account( major credit cards). He said store merchant cards do not really help your score, so stay away from them.
Checking cards, aka debit cards, don't influence your credit score. Major credit cards do. So if your second card is an actual credit card, DO NOT rid yourself of it b/c you want to create credit history as early as possible b/c 35% of your credit worthiness/score is based on 'good, clean, history'. So keep the card and use it. It has to be 'active' to build your score. Make a small purchase and pay it off right away every 3- 6 months. Increase the credit line too. Ultimately, you want to keep your credit balances less than 25% of the total credit line for any one card. The last bit of advice he gave was about credit cards. No two are alike. AMEX, VISA, MC--are the best in that order. From personal research, becoming an authorized user on a parent's credit card can help boost your score too. Their credit needs to be great, the credit card an AMEX, VISA or MC with 25% or less credit balance opened for 6 months or more. Do this quickly b/c FICO is trying to eliminate this from ALL four credit reporting agencies by 2008.
Good LUCK!