Although there may be a multitude of sites, in Canada, the main ones everyone seems to know and enjoy are, in order of preference: Plenty of Fish, Lavalife, and E-Harmony.
Plenty of Fish
Most people like Plenty of Fish or POF because it's free. For the first time experimenter, it's best to not have to pay since you may decide by day three that online dating is definitely not for you. Plus, the lack of expense has attracted many people, therefore, you have a larger base of persons to choose from.
Lavalife
This one is quasi-free. It's free to post a profile and to browse others, but if you want to be able to send messages and actually interact, then you must pony up some dough. I'd say this site is better for girls than guys. Most women, like in real life, still expect the man to make the first move, so guess who has to pay?
E-Harmony
With this site, both sexes have to pay to communicate or receive your matches. What makes this site different than others is that you do not get to view profiles all across the board. You answer an extensive questionnaire, which some one or some computer analyses then sends you matches based upon your answers. This is supposed to eliminate the duds for you and increase the chances of finding the right person or at least find more enjoyable dates in less time. Whether or not it works in practice as well as theory is up for debate, but I've heard mixed reviews and personally found the thought of paying cash up front a deterrent to joining.
What to Post
Once you've decided which site to join - I recommend joining at least two, the next step is to create an alluring and attractive profile. Unlike what some people will tell you, I do not think posting a profile without a picture is a good idea. It's a fact that we need to have physical attraction as well as mental and intellectual attraction. Would you want to date someone based purely on what they wrote? That's not unlike blind dating, which may be fine, but most people join online sites to avoid blind dates...
Choose at least three RECENT pictures. No matter how you might have stayed the same, it's best to be recent rather than choose that great picture from five years ago. I recommend pictures that display you from different angles, different distances from the camera lens, and in different settings. You want to show that you have diverse interests and are flexible enough to be various settings. I also recommend one good picture and two mediocre ones, thus weeding out those who are truly shallow. Anyone with an inch of depth will take the time to know you if there's a chance you could be attractive and are definitely interesting. With respect to “interesting”, take the time to craft a profile that shows who you are. Are you witty? Are you straightforward? Are you shy? Don't be afraid to let you shine through your words. They are the hook to your picture bait.
However, I also warn you in advance that many times, guys will simply email you hellos or send smiles based solely on the picture without even glancing at the words. Take note of who does take the time to read and inquire about your interests. These guys are not the feared “players”. Time is something only good guys and con men will invest. Players online are like players everywhere: they are merely looking for the easiest good time. Listen to your gut. Dating online is not that different from dating in person, pay attention to cues about their personality. Do not down-play red flags. Note their response time and level of enthusiasm. If his picture is attractive to you, his grammar correct, and his conversation decent, it's time to take it to the next level - the first date. There are only two things to remember: have fun and be safe.