First, you have to pick a dating service. Once you do so, you have to write about yourself, or create what's commonly called a online dating profile.
The most important:
1) Make sure you correctly indicate whether you are married or single, and whether or not you have children or want children. Ideally you should be single and say you want to meet someone for marriage and children. If you don't check these things off, you won't meet anyone. Make sure you also check off a profession, and list a body type (slender and/or athletic if possible, never "average") and height.
2) The Intro paragraph. After your photo, this is the most important thing, your main paragraph where you write something about yourself. The key to remember is that people aren't usually selected because of their intro paragraph, but they are often rejected because of it. That's why the strategy of writing the same bland generic things that most other people are writing "I am happy nice and friendly and good with my family" is usually best. If you're a man, women will probably only look at your photo, your height, body type, and profession in deciding whether to contact you. If you're a woman, men will probably only look at your photo, your body type, and maybe your profession in deciding whether to contact you. Your intro paragraph can help, but only slightly, and really only has a potential to hurt you if you write something that potential dates don't like (your politics... your hobbies... your attitudes....). If you have the same general interests as everyone else (eating, drinking, movies), I strongly recommend you go with the bland intro paragraph--write about vague general interests that couldn't possibly offend anyone else and what a nice person you are. You won't stand out, but more importantly you won't offend.
Although I've just recommended going with the bland intro paragraph, there's an exception to this rule: if you don't have the same general interests as everyone else, the bland profile won't work for you. Most people like eating, drinking, museums, and movies. If these aren't your top interests, if these bore you to tears, you're going to have to be honest about your real interests. If you don't, you're only going to attract people who will want to do what you consider to be boring things, and you'll have nothing in common to talk about. A common falsehood is that people with totally unrelated interests can be attracted to each other--well, perhaps this is true of people trapped together on desert islands for months at a time. But people attempting to start a conversation with total strangers need at least something in common. So if you really don't like the typical interests (excessive eating, drinking, drowsy movies, etc.) of most people, you'll need to list your real interests--they will cut down on the responses you receive, but the responses will be more relevant.
I remember I once had a generic profile ("I am nice and like to be nice to the nice"), and I attracted a lot of women and had a lot of dates--most of which were totally incompatible, and it became very frustrating to go on one bad date after another. Then I retooled my profile to specifically list my interests (mine were unusual--excessive eating and boozing were not on the very top of the list), and found the matches I attracted, though fewer in number, were a little more compatible.
The most important thing about your intro paragraph is that you sound friendly and upbeat! No one wants to date someone who is bitter or a sad sack. Make sure you spike your profile in at least 2 places with the stock phrases how nice you are and how you like to laugh. It will sound somewhat insincere to the sophisticated few but at the same time most people will think you friendly, which is important, especially to women.
Also, don't say negative things. "Not looking for someone with an attitude" "I am very picky!" "Not looking to play games" "Don't want anyone who lives near anyone who voted for Bush" are some of the common ones I've seen. Even if you don't want to meet these kinds of people, you shouldn't write it. Writing such thing make you sound cranky, and bitter. Don't list your don'ts. You'll have to do your filtering yourself, in choosing whom to respond to.
In addition to the intro essay your dating service may request other essays (such as your idea of a first date, your interests, most recent books read, etc.) but as long as you don't say anything offensive, it doesn't really matter what you write--the less the better, actually, as the more you write, the more you have the potential to offend. You never know what can offend people or what people will think of your attitudes or interests. What may seem normal to you (such as race car driving or skiing from a helicopter) may seem redneckish or reckless to others. After the intro paragraph, say as little as possible and say what you say in generalities. Think like a politician.
The unimportant:
1) When filling out your profile, there are things that are more important, and less important. The checkbox options where you check off your hobbies and interests are the least important--most people check off a lot of them, and no one tends to pay any attention to them, so don't worry about what you check, as long as you check a few, to make yourself look "well rounded". I don't know how many women had checked "hiking" In their profile when the longest hike they went on was to their local supermarket.
There's also often a section where you're asked to list your income. Don't answer this one. Too low and you'll drive women away; too high and you'll only attract gold diggers. If they only want you for money, you're not going to have a lasting relationship .
