My main reason for blogging is to help writers make more money from their work. These days, for the most part, that means finding a good-paying writing niche. We all know that thanks to the content sites, articles on general topics like how to remove mold from your bathroom may never pay decently again. So what does? Specialized types of writing that require specialized knowledge.

So here’s five of my favorite good-paying writing niches. These are all niches I’ve worked in myself. Next week, I’ll post about more writing niches that I know pay well.

1. Trade publications. This is the niche where I landed my first full-time writing gig. I still freelance for trade pubs, for around $750 an article. Trade pubs usually can pay decently well even though their readership is usually relatively small, because their ads are expensive as they offer a unique opportunity to reach a particular audience.

There are trade pubs in every imaginable industry niche, and they don’t have to be terrifically technical industries. I’ve written for trade pubs about home improvement, restaurant and retail. In healthcare alone, there are more than 20 trade pubs, including America’s Pharmacist, Biotechnology Healthcare, Modern Physician, Plastic Surgery News, Managed Care, and Southern California Physician.

Have you dabbled in a technical field as a hobby, been a legal secretary, a teacher, an engineer, a medical receptionist, or had an unusual college major? Likely there’s a trade publication that could use your help explaining industry trends to their sophisticated professional audience. In my five years writing full-time for a trade pub, we were never fully staffed.

2. White papers. This is the hottest piece of collateral in marketing right now. It’s sales material that doesn’t feel “sales-y,” and it’s incredibly effective in getting clients — see this study for details. If you’ve written articles, case studies or reports, you can easily learn this niche.

I got approached by a communications firm to write a 6-page white paper in ’08 for a Fortune 50 company, and it paid $2,500 – about $1 a word – for my very first one, which was essentially three brief case studies. More complicated, longer white papers pay much more. Follow the masters,Michael Stelzner and Robert Bly, to learn more about this lucrative area.

3. Corporate web content. While writers moan and wail about ads for cheap Web content, major corporations – particularly ones that do something complicated or technical – are paying handsomely for authoritative, well-researched and expertly written Web content created about their products and services. To get the best rates, think big – Fortune 1000 companies or $1 billion+ private companies, though mid-sizers can pay decently, too.

I connected with one global private company three years ago when they were relaunching their complex Web site and rewriting all the content, and made probably $60,000 in several years, just from one client. I’ve been paid $95 an hour and/or $1 a word for content like this, straight through the downturn.

4. Research reports. Do you enjoy sleuthing around and turning up information? If so, there are a number of good-paying gigs writing research reports. For several years, I did quality-of-management research on CEOs of small public companies for investment firms. I’d find where the CEO used to work, research past news clips on the company, find former coworkers, and interview them about the CEO. Took about a week. I got paid $1,500-$3,500 a project, and I found the work challenging and fun.

5. Blogging and social media. I know what you’re thinking – that all pays $15 a blog, right? Not if you’re blogging for major magazines or corporations. I just finished a rush job of 20 short blogs for a business-services firm that paid nearly $1 a word. They were part of a $10,000 package of Web articles and blogs, mostly at the same rate level.

Because it’s so new, it’s great expertise to have and rates are high. Expert Chris Marlow did some research on people who were combining copywriting with social-media expertise in job bids, and found the typical hourly rate they reported was $350 an hour. Take a minute to absorb that concept!

I believe social media is the hottest new writing opportunity out there. You just need the right kind of clients. In the last half of ’09, I signed my first few clients where article writing is coupled with social media – blogging for them on other sites and/or tweeting on the company’s behalf. I did one $1-a-word article package recently for a major company’s Facebook fan page. If you enjoy social media, the work’s fun. Often, the marketing exposure’s great, too…and I expect this niche to boom in ’10.