Rep Power: 650

Installing 2 electric fans out of 95 grand prix . So far not 2 bad , fabed up brackets etc & they look not bad .Been out 4 a burn & they work ok. Now the wiring thing I'm told i need relays, how are they wired in and why , a diagram would be nice as this is 4 an older 78 camaro. Ihave 1 wired constant and 1 to the ign. in the fuse block. I'm also told i can wire in manual switch to over ride fan sensors, how do u do this?Whats the best way to build fan shrouding , type materials etc. where would i find a front air damn 4 the camaro, this is 4 aZ 28 ,1978 with buick 455. as always thanks 4 the help & have a great summer . Bake