Don't hesitate to also look online for cultural information--be creative and relevant to your needs. Do you want to know what fans think of a Latino hip hop artist? They may not be listed in any book, but you may find reviews anywhere from a credible online music magazine to even online forums dedicated to the artist (obviously, the usual caveats apply to using an online forum!).
Just a couple examples--search or browse for more!
Just one example! Search and browse for many more!