In most cases, you’re going to have a pretty good idea of which publications the people who you sell to read. But you'd be surprised at all the publications that are out there that you may not have thought of. So here are some places to look for publications that might be a really good fit with your how-to articles:

The Bacon’s Directories
Most major libraries have the Bacon’s Directories. You can go to your particular topic and find all kinds of magazines, both business-to-business and consumer magazines, that might be interested in the particular article that you happen to write.

Writer’s Market
It updates its book every year. You can get the Writer’s Market at any major bookstore.

On the Internet
You can do an Internet search for electronic newsletters that serve your niche market.

Ask your customers
The best way to track down publications that you want to get into is to ask the people who are already buying your products and services what publications they are reading, and ask them to give you some sample copies.

For more publication resources check out How to Write How-to Articles for Newspapers, Magazines, and Trade Journals