I'm a veteran linux guru..
I know it sounds smug, but really, I've been using a Linux desktop exclusively for 13 years now, since the 0.99 Linux kernel, HPUX before that, and it's my full time job.
To stay on-topic, checkout Rosegarden for sequencing and recoarding. Also see GLydian on this group if you have a G*Major effects unit. The windows version of the FCB1010 midi pedal editor works great on Linux with the win32 api layer called "wine."
Microsoft products are not allowed in our house. It's incredibly liberating.
--edfardos