Security: Denial-of-Service, security in hostile environments (software protection, white-box security), Phishing, Spoofing, Spam, Malware, DNS poisoning...
Cryptography: provable yet applied. Esp.: protocols, robust combiners, resilient & proactive security
Network protocols and distributed algorithms, esp. peer to peer and social networking, vehicular networking
Functionality > Usability > Reliability > Performance > Security > Privacy
Search and read - a lot... use keywords and previous articles to find new works. In particular try Citeseer (or new version Citeseerx), Google Scholar and ACM Portal. Citeseer and Scholar are especially handy in finding citations (papers citing a publication), which is crucial for searching an area. Many articles are available online, some only with subscription; most universities and in particular Bar Ilan has online access to many sources. Scholar also produces BibTex citations (but not by default - set preference), but often better citations are in the Collection of Computer Science Bibliographies or in DBLP.
Improve your (English) writing style. Two great online sources: Lynch's guide to grammar and style, and the very concise Strunk's `The Elements of Style` (this online version is 1st edition; I use 3rd edition, by Strunk and White).
Write using LaTeX, e.g. with TeXnicCenter, and using BibTeX for citations. I use, and recommend, the Algorithm2e package for writing algorithms and protocols. Comment: one of the lesser advantages of LaTeX, is that it can create PDF and PS (postscript) documents. For figures, I recommend Open-Office which also makes great PDF and PS output (or see more PDF/PS tips).
To find conferences: use confsearch or, for security CFPs, see collections UCL and IEEE.