Relay for dummy!!

Ok so I used to install remote starts, and alarms professinally some years ago. I would like to start doing it again. I just would like a littl einsight, a diagram would be great if available.  basic relay uses are:

NEG. To Pos.

Pos. to Neg.

Low volt. To High Volt.

High volt to low volt.

If someone has so diagrams to explain what pins connect to where, I would very much like to have them.              THANKS

HIGH VOLT TO LOW VOLT NOT happening.,  

neg to pos

pin 86and87 pos 12

pin 30 output

pin 85 negative trigger.

basically whatever you want to come out of pin 30 you need to put into pin 87  and use a pos and negative through pin 85and 86 to activate it . 

low volt to high volt is

pin 87 pos 12

pin 85 ground pin 86 pos trigger 97a not used and pin 30 is your output.

pos to neg is 

negative on both 86and 87 87a not used , pos 12 signal to pin 85 and 30 is output.

So djfearny yo say That it sno possible to change a high voltage pulse into a lower voltage pulse?