Vi (or vim) is by far the most commonly used editor. It takes a while to get used to though (I still know hardly any of its tools).
If you are looking for a very similar 'simple' editor (like pico) then nano is available (I have FC2 and its on there).
Regarding midnight commander, I have the following alias that was already set for me:
alias mc='. /usr/share/mc/bin/mc-wrapper.sh'
It may well be the case mc is not included in FC3 - see if the /usr/share/mc/ directory exists!