Your first meeting should be in a public place and you should let someone know where you're going. Don't expect everyone you meet online to be Mr or Ms Right. The typical online dating service is free to join. The amount of detail varies from one site to the next. It's also free to browse the profiles of other members, either clicking your way through the entire directory or setting a range of criteria to narrow your search.
Some sites allow a greater degree of focus than others.
For example, on RSVP you can get down to the level of seeking a non-smoking, social drinking, slightly overweight Middle Eastern vegetarian man between 30 and 35, who has children and lives in the southern suburbs of Sydney. Most sites hit you in the wallet only when you want to e-mail a member whose profile you fancy. Your message is automatically forwarded to the private e-mail address of your love interest.