Facebook Friends?

For the longest time, I resisted joining Facebook.  I have nothing against it, I just wasn't into the social networking thing.  I am in LinkedIn, for business networking.  However, last September or so, one of my business contacts started a Facebook group so I reluctantly joined.

I will say I am now enjoying Facebook to a degree.  There are people I've know from high school that I have kind of reconnected to.  Some business contacts I've known only by phone I now have more of an understanding.  But there is a dilemma.  Who exactly is a "friend"?  Here are people who have been suggested to me recently.

• The younger brother of a high school classmate of mine.  I'm not sure if I ever traded two words with him.
• Many people who work(ed) for my first employer out of college.  Many are good friends/acquaintances.  I'll have to dig through those deeper.
• A female 1 year behind me in high school.  The name sounds familiar, but that was so long ago, I don't know if I really knew her, I knew a sibling, or what.
• Various people from a professional listserv I belong on.  Those should be fine, as I'm Facebook friends with others on the list.
• This girl who I worked with during high school.  She also went to high school with me, but I think a couple of years back.  The thing I remember the most about her?  She took me, a mutual female friend who also worked with us, and our not-quite-out hispanic boss to a party themed by her Asian ethnic background.  Oh, and she was trying to "turn" said boss.
• People who I may or may not have had class with at the University of Maryland.  Hey thousands of students in each graduating class, I can't keep track of them all.  Besides, I read the Diamondback everyday.  Some of those names were reporters/editors for the paper, I think.
• Finally many random people who happen to be friends of friends of mine.  I can't fault Facebook on those.

So really, who do I choose to be Facebook friends?  I guess each person has to decide on their own, but I don't know if I should be "friends" with all of the above people.  What's funny is I've had more interaction with some bloggers than some of the people Facebook has been suggesting to me.