Its probably worth forking out and becoming a member of an established dating site, free ones tend to be populated with skinflints, weirdos and Nigerian scam artists.
Take time to write a decent profile, get a friend to proof read it and offer constructive criticism. While you are trying to 'sell' yourself in the best possible light dont embelish things too much, playing tennis on holiday a couple of years ago is not a hobby! If you describe yourself as 'athletic' make sure you are!
Dont spend forever exchanging emails, swiftly move to chatting on messenger then a chat on the phone if you are comfortable (withold number), you will find out volumes more about a prospective date as emails dont always convey personality, humour etc.
Set up an email address spefically for the use of dating
Honesty is the best policy, if you dont fancy someone after a date a polite 'had a nice time but I dont want to take things further' would be appreciated rather then just a rude radio silence
Always stick a photo(s) on your profile, preferably recent and make sure you don't have your cropped out ex's arm draped around your shoulder.
Your gut feeling is usually the right one.
Arrange first dates as a lunch or simple drinks after work, you dont want to have a 3 course meal only to find the chap is a complete bore and you have no easy escape.
Always tell a mate where you are going when meeting someone for a date.
Come up with something more original then 'likes a night in on the sofa with a bottle of wine and a good DVD'
Don't post photos of your cat.
Don't get upset if someone you like who you went on a first date with is on the dating site the following day, that is allowed. It's not uncommon to have a few irons in the fire when online dating until things get a bit more serious.
Have fun!!