Tell me about Caller ID

We just had Caller ID installed, after spending several weeks getting hang-up calls. We would do *69 back, but get a message saying the number of our last incoming call was marked private.
We bought the phone Thursday, and Caller ID was activated Friday.
I already did the *77 to block anonymous calls.

I’ve been on hold for over an hour with Verizon to ask some questions, but I know I’ll get some answers from the esteemed Teeming Millions.

What does it mean when an incoming call says “Out-Of-Area” or “Unavailable”? They aren’t the blocked calls, since I’ve blocked the blocked callers.
Sometimes, it will say “Out-of-Area 000-000-0000” and will be a telemarketer or something like that (someone from Comcast trying to upgrade my service).

When my husband calls on his cell phone, it says “Out-of-Area” but still lists his cell phone number, even though he’s only 10-12 miles away. Why?

What do I do to block my outgoing calls?

Anything else I should know about using Caller ID? Good or bad experiences? (I’m not going to be one of those obnoxious people who calls everyone back and asks who they are and why their number is on my Caller ID.)