I agree with Eliza Jane. It's fine to make the first move but, more often than not, if the guy is interested HE will contact you. Unless there is that initial physical attraction (based on your photo), it's probably not going to lead anywhere.

Also, if you do send an e-mail to a guy, and you don't get a response, I would advise against sending a second one. If he's interested, he'll definitely contact you. No response = not interested. Therefore, multiple e-mails is usually a big turn off. (At least, it was for me when I was online dating!) It makes you look desperate and like you're not getting the hint.

Best of luck! I met my girlfriend 1 year ago through an online dating site, so it really can work!