My advice is to only use dating sites where you have to pay to join.
and then be very very carefull.
those places are full of right freaks.
You get the obvious ones who just want sex. you get the socially inept ones who just aren't capable of meeting someone in RL as they just can't string a sentance together.
Then you get the worst kind. The emotional sponges. within the first few emails they are sending you their life story, complete with the full low down on how horrible the ex was and how evil she was to dump her the way she did...he was only trying to be a fabulous boyfriend after all.
they make everything about them and what they want...which is a mother usually.
they jump straight into the "so when ca we meet" "what sort of relationship do you want" "shall we live together or get married first" everything is rushed. not because they have fallen head over heels for you but because they are just desperate to have someone anyone, just so long as they aren't left alone to have to deal with their lives like a proper adult.
they are like plagues. they come across as very nice and polite but they are like a rash. one slightest hint of being friendly and they think they are in. but don't think youwill hurt their feelings when you realise how stiffling it is to be with them, they will be back on plenty of fish before you have clicked send on the email.
If you want a bloke the best place to look is in the real world. where you can spot their weirdness in teh cold light of day