2001 Honda Shadow Questions

I've scoured the interwebs for simple questions regarding my bike and have thus far found nothing helpful that didn't require a paid for subscription... Seriously? I own a 2001 Honda Shadow and was wondering about basic maintenance, like oil specs, spark plug gapping, the usual stuff that's included with the bike.

To be specific I was curious about the oil requirements and after my bike's battery died at McDonalds on my way to work, only after dissembling the bike did I discover that which Clymer's holds so dear. I live in Florida which gets a lot of rain, so I was concerned.

The 2001 Honda Shadow uses by default 10-40W oil, and while they don't recommend bump starting or jumping off a car battery (both of which I call BullCrap on). They conveniently suggest contacting the dealer. I did perform a jump twice, with no issues. What I didn't know was that the bike was supposed to be trickle charged every 30 days. She's charging now, but I digress and ask is the battery supposed to be draining if the power and engine switch is turned off? By my rationalization, there should be no load or closed circuit on the bike when everything is turned off. Please correct me if I am wrong.

Will