Three quick notes about literary agents:
Most agencies have websites. I strongly suggest going to their website. This way, you'll ensure the most up-to-date information regarding the literary agency you've targeted. If they don't have one, that's okay.
Also, be sure to check out AAR's website. This is the Association of Authors' Representatives. The AAR has a strong code of ethics and is an agent is reputable, they're most than likely members of this organization. Their website is http://aaronline.org/
Lastly, the Science Fiction and Fantasy Writers of America has a terrific website which lists literary agents that may be dishonest/scam artists. It is also a great tool for compiling yet another list of agents. Their website is http://www.sfwa.org/for-authors/writer-beware/agents/