On building credit, here are some things that might help:

1 Check for any pre-qualifying options first before trying a credit card application. Hard inquiries are made whenever you apply for a credit card and can hurt your credit score.
2 Stick to two credit cards max
3 Pay back more than you owe when you use your credit card for a purchase if possible
4 Discover, Capital One, and American Express seem to be most open to new lines of credit. Capital One is the best option because of later perks and limited acceptance of Discover and Amex in some cases
5 Try to utilize no more than 25% of your total credit when making purchases
6 ALWAYS pay back on time...next day if possible