It is always nice to work in an UNIX environment. The variety of tools and utilities is incredible and many have been refined over decades to be fast and efficient. I'm a big fan of the Slickedit editor (as evident by the fact that I have a forum for it on my site), but alas Slickedit discontinued the version that runs on the platform I use at work so it is no longer an option. The two heavy weights of editors are EMACS and VI, but I'm not going to go in to a holy war about which one is better. I've always been more of an EMACS guy, so I picked it up again and started to get my proficiency back (not that I was very proficient to start with). I think it's good to also know more VI so I'll probably try to spend some time with it also, but for now I'm using EMACS. As powerful as EMACS is, I sometimes miss the ease of Slickedit.
I got "Learning GNU Emacs 3rd Edition" and "Learning the vi Editor 6th Edition" (both published by O'Reilley) and I would recommend the EMACS book if you're just starting out. It is clearly written, very practical and has good real-life examples. The VI book is only so-so. I got the basics of VI from it but really didn't feel I learned any new "tricks".