My favorite book on writing is Stein on Writing, which has advice for both fiction and non-fiction writing. Possibly the two most important points of his are that non-fiction should not be dry, and that you should ideally grab your reader's curiosity from the very first sentence. If that doesn't work, then at least from the very first paragraph. That's more important than ever online, where the reader can always find something more interesting to read if an article seems boring. (I don't follow this advice nearly as often as I should.)

Here are some of his examples on good non-fiction, excerpted from real articles:

When it comes to shopping for a computer, the most important peripheral runs at 98.6 degrees Fahrenheit and is known as a friend.

Here on a stony meadow in West Texas at the end of 10 miles of unpaved road through mesquite-covered, coyote-infested shurb land, several hundred bearers of a strategic commodity of the United States of America are gathered.
They are goats.

As the 155-millimeter howitzer shells whistled down on this crumbling city today, exploding into buildings all around, a disheveled stubble-bearded man in formal evening attire unfolded a plastic chair in the middle of Vase Miskina Street. He lifted his cello from its case and began playing Albinoni's Adagio.

Repetition is sometimes a useful technique:

Yesterday morning Henry Sorbino walked into the K-Mart on Eleventh Street carrying an umbrella and walked out carrying an umbrella and someone else's purse.

Adding color can be done subtly - note the one word that makes this sentence more interesting:

At exactly 10:19 A.M. yesterday, a grandmother's purse on a conveyor belt at Orange Country airport set off an alarm that caused two security guards to rush to the scene.

An otherwise uninteresting piece of news can be made more interesting with an eye for detail:

Carl Gardhof, his head held high as if he had done nothing wrong, was sentenced in Superior Court to eighteen months in jail this morning.

Note how much better the preceeding sentence works than if we'd used the cliché of "maintaining his innocence".

The real subject of the next story was the suspension of auto union talks because workers were loath to chip in for health care costs:

Since learning last year that he had multiple sclerosis, Andy Torok has become less and less steady on his feet, and his worries have accumulated along with the hand prints on his apartment's white walls.

An obit or memorial piece doesn't have to be dull:

Andy Warhol, draftsman of shoes, is dead, and the people viewing his remains are mostly wearing scuffed white sneakers.

A year after his death, the recurring image I associate with Raymond Carver is one of people leaning toward him, working very hard at the act of listening.

Nor does the opening of an autobiography:

Many problems confront an autobiographer, and I am confident that I have not solved them.

I see no reason why the reader should be interested in my private life.