void :
don't want to be a nitpick but usually it's desirable to put $PATH at the end, not at the beginning. I.E. qt defines a QTDIR, $QTDIR/bin is in your path, if you use multiple qt version typing export PATH=$PATH:$QTDIR/bin is not the same as export PATH=$QTDIR/bin:$PATH (in the first case, the $QTDIR/bin already present in the path will be used)
bob:
/bin is for normal binaries, /sbin is for binaries which require root priviliges (if I'm not mistaken)
Calum's answer is also entirely correct ofcourse though