Apply for a small loan or open a credit card with a local business, community bank or credit union. They typically have lower credit history requirements than some of the larger lenders. Another option is to get a secured card. Before applying for any of these options, make sure the account will be reported to at least one of the major U.S. Credit Bureaus; Equifax, Experian, or TransUnion.
The Bureaus use payment history to calculate credit scores therefore it may take 6 to 9 months to build your file. In order for your score to be in the 700-800+ range, make sure all of your payments are on time and keep the balance on your credit card below 50% of their card limits.
There are several companies that offer credit cards on their sites. We suggest starting with Cornerstone Client Solutions - their focus is on credit cards that assist people looking to establish or rebuild their credit scores.
Also, the FAQ section of our website contains other helpful tricks for people looking to do DIY credit repair.