Thanks to all who took the time to reply.
It seems there are a few differing opinions. At least I know I can
drain the moisture without having to bleed the tank down first. As far
as emptying it completely, I guess that's not really such a big chore -
as one of you mentioned, it's only a 20 gal tank so recharge doesn't
take that long.
In all probability, knowing my past habits, while it's new I can see me
doing everything by the book initially, but after the novelty wears off,
I'll likely tell myself I'll "do it next time".
I'm a complete novice to air tools and their use. No doubt you'll be
seeing other naive postings from me from time to time until I get the
hang of it. I hope you'll be as tolerant with me then as well.