One of the tools I've come to rely on to keep my career development skills sharp are the CrossRoads jobseeker New emails from Net-Temps.  Their topical and filled with useful tidbits anyone who proactively manages their career can use.

If you are un(der) employed, insecure about your current job, or just want to sharpen your job seeker tools, open an account there and sign up for this email. It's worth it. 

Recent topics for job seekers are:

How to Manage Your Career During an Economic Downturn

Honesty in Interviewing

10 Things You Must Do Before That Successful Interview

Emailing Your Resume

Four Cover Letter Secrets To Get You The Job Interview

Ten Things a Recruiter Will Never Tell You

Five Questions to Always Ask on an Interview

Employers and Recruiters Know How to Read Resumes