The most simplest pipeline is by using latches. Consider a ckt with combinational blocks connected to each other..i.e, the o/p of the 1st block goes as i/p to the next and so on.till it reaches the last o/p stage.. To pipeline this , we simply latch the data between each stage and use a common clock for these latches. This is the simplest pipeline.
In the processor's context, pipelining means to duplicate the basic units, ie, IF,ID,EX unit. If you'r implementing 5 stage pipeline, then u duplicate these blocks 5 times.
What I've said here is just the basics.. there are other considerations to be taken care of when pipelining.