Librarians' Index to the Internet - One of my favorites for starting a new subject search, the LII is a searchable, annotated subject directory of more than 8,300 Internet resources selected and evaluated by librarians for their usefulness to users. Tip: try a search for "databases" along with another word
SearchIQ - now owned by ZDNet - this guide contains thousands of specialized search engines organized into 24 subject categories and and many subcategories
About.com - Once a big favorite of mine, the About network consists of over 700 Guide sites (guides are editors, each covering a topic). The sites cover more than 50,000 subjects. Unfortunately going through some "restructuring" which has sadly started to affect the results with more broken links and redirects--in one case I was sent to a porn site thinking I was going to a sales site, that was interesting (but I guess that is sales, isn't it?).:-) Just do a search for your subject, you can be a bit more specific with this one
Statistical Resources on the Web - (from the Documents Center at the University of Michigan Library) - A misnomer, it is not restricted to statistical resources by any means. I suggest you pick a category first, then click to remove the frames. Then grab the scroll bar to quickly scan as each page is long; better yet use the "Edit - Find" feature on your browser (see my note below if you don't know how to do this)
The Internet Public Library (IPL) - is a public service organization and learning/teaching environment at the University of Michigan School of Information. Loads of links here, subcategories list sites that are more commercial in nature rather than government/academic as found at Statistical Resources on the Web
SearchEdu.com - Over 15 million university and education pages indexed and ranked in order of popularity. When you search this one use quotes around phrases and be as specific as you can. Search.Gov and Search.Military links are also available on the page.
Google Groups, aka Usenet - Use this to search the entire archive of 600 million Usenet discussion posts from 1995 to the present. I recommend you use the Advanced Search option for the best results, for example, omit the word "opportunity" if searching for any business oriented messages to help minimize blatant ads from the results. Also be specific.
FinderSeeker - Billing itself as "The Search Engine for Search Engines", it is best used like SEC above to find obscure country SEs which will hopefully lead you to the information you seek. Hint: Choose "All" for Category and leave the Keyword space blank, just choose the country
FreePint - Excellent for keeping up with resources Online, reviews resources, with an emphasis on UK and on business.
Beaucoup - Oldie but still a goodie
Although in this post I tried providing links to well-rounded sites that can help you find the deeper information regardless of your field of interest, given the nature of the message board here are a few decent business directory sites that you may find quite useful:
Business.com - Huge database of everything business. Unfortunately you have to pay to be included but all submissions are managed by editors (especially understand given the price tag, if you recall the Business.com domain name sold for over $7 million back in the Net heyday). But it is an excellent database of information with more than 400,000 listings within 25,000 industry, product and service subcategories.
The New York Times page of business links - (aka Business Connections) - a good starting point for company or investment research in particular (registration is necessary but its free and will also allow you to access the rest of the NYT's site)
The Federation of International Trade Associations - More than 4000 links to International Trade / Import-Export Web sites are annotated and indexed, best to browse by category or to search by country or region
CEO Express.com - You will surely like it. But don't forget to come back soon!