Friends or "Friends"
When is the right time to become Facebook friends with the guy I'm dating? (We met online).
Friends or "Friends"
I'm pretty sure the right time is when you don't have to ask about it. Think about it this way: If it's time to change your status to say "in a relationship with his name here," then it's time to be Facebook friends with him. If you have gone through the DTR (define the relationship) phase and have determined that you are seeing each other exclusively or that you are just going to be friends, then either way, you won't have to worry about exposing information about your current dating life through your photos and status updates. Your past dating life is another story, though, and this new guy could be a motivating factor for cleaning up your profile (or "timeline") to erase previous escapades.
For the record, had you met through friends or at a social event, my advice would be different, since Facebook is especially good at connecting friends of friends, and there are potential benefits to seeing how he interacts online with his/your friends while you're in the process of getting to know each other. Also for the record, let's be clear that he has already looked you up on Facebook, and you've already looked him up. Perhaps you discovered that you actually do have some mutual friends or that you both "like" the same brand of detergent. Do not mention these things in conversation. Until you are actually dating and actually Facebook friends, I seriously forbid you from mentioning anything you learned about him on Facebook. Seriously.
There's something else to consider, which is: Why do you want to be Facebook friends with this person? This is a question to ask whether we're talking about a guy you're dating, someone you remember from elementary school or the friend of a friend of a friend who you met in a bar over the weekend. If the reason is just to collect people on Facebook, it's not a good one, and you might want to save yourself the click. If the reason is to appear more popular or more interesting or more connected, you might want to take a look at how you're using Facebook and how you come across as a result. (You still might decide to friend the person, but it's worth some self-reflection first.) If you really feel a connection with this person and want to be able to stay in touch, go for it, but then make sure you're treating the person like a friend and not like a number. (All of this, of course, doesn't apply to those of us who are Jewish professionals and shamelessly use Facebook to promote events! I have been told that my friend list is a great source of information about who's involved in the Jewish community in Philly, but if that's not your business, I stand by my advice to stick to a closer circle of friends.)
Good luck with the guy, and be well,