I use a MIDI keyboard to enter my sequences with. Digital audio recording is done using a variety of mixers and microphones. Keyboards and bass guitar are directly connected to my mixer. I don't record live drums, instead requiring that drummers play pads connected to MIDI triggers and then I save the drum performances as a part of a MIDI sequence. Think creatively and maybe you'll make it big - never assume that you won't have to work for it.
Nothing is ever as easy as it looks.