My advice? Secure a record of everything I ever did while dating online, study it, and do the polar opposite of what I did.
But in seriousness, be careful. I would recommend a dating site, preferably a subscription based one if you can. That naturally filters out a lot. I would wait for the guy to initiate, but that's me, and I'm old fashioned.
Meet in public for the first few dates, until you feel secure/safe with the guy. It is, mostly, a pure safety thing, as I understand it.
The biggest thing I can offer? Be honest. Totally honest. Type as you would normally speak. Don't filter yourself (aside from the natural "Let me not blurt everything on my mind" filter

). You don't want to create an image of yourself that doesn't match you. Additionally, be very mindful of how easy a thing that is to do. Falling in love with that you think someone is can be an awful thing to do.
At the same time, I just got out of a relationship that started (and ended) online, and I just did quit that aspect of dating because of it. I wouldn't call myself bitter over it, but I am biased against it. Thus, take my advice with a grain of salt.