The links below connect to pre-screened career-related websites that have proven to be excellent resources. Many are free to use, and some require a monthly charge of under $50. Your e-mail recommendations are appreciated for sites that are particularly useful and not listed here. I've also included a few old-fashioned (i.e. non-Web) resources.

www.fiveoclockclub.com - the best methodology I've seen for finding a job or changing careers, and the one that I use.

Industry & Occupation Research

online.onetcenter.org/ : ONET Online-- A great site for researching hundreds of occupations and developing job targets.  Also, check out their self-assessment tools, which match up your interests, talents, and work-related values with their job descriptions:

• http://www.onetcenter.org/AP.html : ONET's "Ability Profiler"
• http://www.onetcenter.org/IP.html  : ONET's "Interest Profiler"
• http://www.onetcenter.org/WIP.html : ONET's "Work Importance Profiler"

http://www.mynextmove.org/ : My Next Move:  Another take on the ONET information-- helps to identify interests by job category, skills needed to pursue those interests, and the outlook for different professions.
www.bls.gov/oco/ : Occupational Outlook-- thousands of occupations, including projected growth rates-- great for brainstorming careers, although a bit overwhelming.
www.virtualpet.com/industry/mfg/mfg.htm : Comprehensive collection of industry portals- great for research.
www.wetfeet.com : Great source of industry analysis.  
www.Vault.com : Industries, and info on more than 3000 organizations, from jobhunter point of view. (* site has been slow to load lately)
www.hsCareers.com : Lots of information about the human and social services sector, including position descriptions.

Associations
www.job-hunt.org/associations.shtml : Nice directory that shares descriptions of the associations and reasons for joining.
www.asaecenter.org/Community/Directories/AssociationSearch.cfm : Find your associations by typing in your search criteria.
www.ipl.org/div/aon : Associations on the Net - good.
www.meetup.com :  Groups of varying quality for every interest or profession.  Worth checking out.
Encyclopedia of Associations - at local library. Best source.

Below I've listed associations that I've either had had personal experience with or heard about from clients, in terms of fostering career development and new network contacts.  Most or all have local chapters and sponsor LinkedIn Groups.  If you are a client or colleague feel free to suggest others for this list.
www.cscmp.org :  Council of Supply Chain Management Professionals
www.mengonline.com : Marketing Executives Networking Group
www.thefeng.org :  Finance Executives Networking Group
www.cfaphil.org : CFA Society of Philadelphia (Chartered Financial Analysts).  Many other local chapters, access via the "CFA Institute" website at www.cfainstitute.org/society/societies.html .
www.afponline.org/ : Association for Financial Professionals
www.theteng.org : Technology Executives Networking Group
www.odnetwork.org : Organizational Development Network
www.astd.org : American Society for Training and Development
www.pmi.org : Project Management Institute
www.naspp.com : National Association of Stock Plan Professionals 

Salary Research websites
Use these websites to research the average salary for your target.
www.glassdoor.com   Very useful because all based on reporting from service users- on their actual salaries at different firms.  You must share your salary at a prior firm to gain access.
www.salary.com
www.payscale.com
www.jobstar.org/tools/salary/index.php

Job Boards

Sites that pull listings from many other job-boards
www.indeed.com : Aggregates job postings from a broad spectrum of job boards, saving you time.
www.simplyhired.com : Another useful job-site aggregator. 
www.linkup.com : focuses on positions posted on company websites (the benefit here is less "junk")
http://www.odinjobs.com/ : Aggregates IT job postings into one location.

Individual job boards
www.careerbuilder.com : Search for jobs, post resumes.
www.monster.com : The list wouldn't be complete without it.
www.nytimes.com : Click on "job market" on the upper left, they have a good selection of help-wanted ads.
www.craigslist.org :  Many local-market jobs are listed here.

Job boards focused on certain industries or professions that have been recommended
www.idealist.org : Jobs and volunteer opportunities at non-profits.
www.volunteermatch.org : Find out about volunteer opportunities- could jump-start your next career.
www.socialservice.com : Great job board for social service positions.
www.dice.com : Great job board for Tech/IT positions.
www.ejobs.org : Great job board for Environmental jobs. Includes a state by state listing of Environmental employers.
www.higheredjobs.com :  Faculty and administrative positions in colleges and universities.
www.mandy.com : International film and TV production-related jobs are listed here.
www.mediabistro.com : Journalism, TV, screenwriting, and other multimedia jobs.

The following job boards are fee-based or member-based, targeted to $100K-plus jobs:
www.6figurejobs.com
www.theladders.com
www.netshare.com
www.execunet.com

The following job boards highlight companies that have expressed a commitment to hire older workers:
www.jobs4point0.com : For 40+ .
www.retirementjobs.com
www.seniors4hire.com
www.yourencore.com : retired engineers and scientists
www.seniorjobbank.com

Other
http://www.employmentwebsites.org/website/tree : International Association of Employment websites.  Search for specialized job boards by industry/profession and geographic area.

Companies / Organizations
www.spoke.com : Clients are using this site successfully to identify hiring managers at organizations, including their contact information.
www.zapdata.com : For a nominal fee, create a prospect list of companies in a geographic area with contact names, for a Direct Marketing campaign.
www.jigsaw.com : Another site which has reportedly been useful for clients in obtaining contact names and information at organizations.

www.carolworld.com : Annual reports for companies around the world.
www.bigbook.com : Great source for company information.
www.downside.com : Direct access to latest company financials including 10K and 10Q.
www.guidestar.org :  Research non-profit organizations
www.fortune.com : The magazine's website- find lists of the best companies to work for. May need to subscribe, but inexpensive.
www.highbeam.com : Good for small companies.
www.prnewswire.com : Great site containing organization press releases. 
www.libraries.rutgers.edu/rul/rr_gateway/research_guides/
busi/company.shtml : Great site for researching companies. National, plus focus on New Jersey.
www.virtualchase.com/topics/company_information_index.shtml: another great company research site.
www.learnwebskills.com/company/ : step-by-step tutorial on researching companies, including non-profits- great site.

Other
www.taprootfoundation.org: The Taproot Foundation places professionals in non-profit organizations for pro-bono projects.  Could be a great way to build experience in advance of a career or industry change, to fill in a resume gap, or just to do some good!
www.visualcv.com : For Graphic Designers, artists, people who need to show visual  samples of their work-- good place to post samples without building your own website from scratch.

General
Google email alerts:  Set up an email notification if a topic you are interested in (e.g a company in your marketing plan, a leader in your target profession, etc.) surfaces in the news.  1) Go to http://news.google.com  .  2) Do a search on the topic, until you have used the right search key words to generate a useful search on the topic.  3) At the bottom of the page, select "create an email alert for <topic>".
www.fastcompany.com : Go to the "Guides" section, some great articles about careers and succeeding in your job.
www.highbeam.com : A great site for research since contains content not on the "free" web- need to register. Encyclopedia of Business Information Sources - library. Select any topic- will tell you journals, associations, websites. e.g. Rug industry, oil, banking, etc.