Old you might be, Hero45, but not as old as some of us! :P
Oddly enough, I started out on Pokemon Crystal before I went to R/B/Y: Crystal was what converted me into a fan. So yeah, it'd be a good idea to get hold of a copy or copies of G/S/C to play.
The only relationship between G/S/C and R/S that I can see is that certain concepts put into G/S/C were refined in R/S. I'm thinking along the lines of Berries, and breeding pokemon. there were also mini games as well, such as the ruins of Alph to complete, and rare pokemon to hunt down.
Crystal is different from G/S only in the way you can get the three legendary dogs and the two legendary birds. In G/S once you'd completed the radio tower and freed the radio manager, you were given either a silver or rainbow wing, which allowed you to go for the version exclusive LB. Once you'd beaten the elite 4, you were given ticket to Kanto, and you eventually got the other wing, which allowed you to go for the other bird. The LD's were running around loose in the grass, and you encountered them at random.
In Crystal, your reward for freeing the radio manager was a clear bell which you had to use to reach the tower where Ho-oh and the dogs were. You were allowed to try for Suicune here. you then had to track down the other dogs, because catching them was the only way you'd get to ho-oh ( trading for the dogs didn't work). Again, once you beat the elite 4 you got a ticket to Kanto, and you'd eventually get the silver wing which would allow you to go for Lugia.
This is only a rough outline: no doubt I've forgotten a lot, and others will fill you in more.