i got problems with downloading my minecraft mods

Question

please i always wanted to download mo creatures mod or... jurassic park mod, too many items, and twilight forest mod...i really wanted to nhave them but now i got a question... do i meed to download winwar to have mods and mod loader??? because i know i have to go to all those folders and delete stuff. but when im like on the bin one i think it says an arror could not do it or something. like i think that i need to download something...?!