How do you put on a huffy beach cruiser bicycle chain?

Depends on what you want it for. Beach cruisers generally are heavy, offers an inefficient riding position with low gearing and poor brakes. For a bike to actually go somewhere with they're not a...

To keep it from rusting, to reduce wear and unwanted friction.

Depends a bit on which type of bike it is. I'll add a link where you can see more.

my huffy roadside cruiser is from the early sixtys

Quite probably. Exactly how depends on what kind of brake it is. You can find loads of tips on www.sheldonbrown.com, www.parktool.com and www.bicycletutor.com.