89-850 Communication networks and protocols (spring term)
89-550 Applied network security (`ethical hacking') (spring term)
Security: Denial-of-Service, security in hostile environments (software protection, white-box security), Phishing, Spoofing, Spam, Malware, ...
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
Search and read - a lot... use keywords and previous articles to find new works. In particular try Citeseer, Google Scholar and ACM Portal. The first two 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.
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 from 1918; I keep and 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 (or see more PDF/PS tips).
Network! See e.g. A Guide to Professional Networking Skills and a computer science graduate school survival guide
Submit... See e.g. collections of Call For Papers in security at UCL and IEEE.