having a clutch problem

ive had a problem i get a bad rattling when starting(stopped) out from 1st gear. when i engage clutch it seems to slip a bit(while rattling) then after clutch is engaged its fine. only does it when starting out when completly stopped. also does it when i go reverse. i have to ride the clutch in order for it not to rattle. it is also hard getting into gear. what could be causing this?