Once your carefully chosen title has lead someone to the article you wrote, the first thing he's probably going to read is the lead.
The leading paragraph is often, like in newspaper articles, printed in bold. Hasted readers scan articles and often read nothing but the lead. They know that good leads contain the principal information. Only if they are really interested in knowing all the details about the article's subject, or if they have plenty of reading time at their disposal, they are going to read on.
So your goal is to convince the reader to read on. You've put a lot of effort in the writing process, and maybe you've got some adsense or affiliate links in your online article through which you want to make a bit of extra money. This means that the readers should read or scan through the article in order to see - and hopefully click on - the ads.
How can you accomplish this goal?
First of all, the first sentence should be intriguing, filled with energy, intrigue and full of forward momentum. It should tell the reader what he is about to learn.
Good articles, like stories, contain tension arcs. The lead is a good place to put your first one. You could do that by telling a story.
As a child, every year on my birthday, I would wake up to the smell of freshly baked bread, canola pie and hot chocolate. When I came down for breakfast I would see a huge pot of bubbling soup with spatters all over the stove. My mom would wake up super early for a fantastic meal at our family table.
Stories are a great way to connect with your readers. They paint pictures in their head, they make them relate, elicit memories and feelings.
Interesting ways to start your story are to begin with a question, a sound (onomatopoeia) or a description of the setting.
If your lead is exciting enough, it will definitely lead your readers into the rest of your article.