As an employer it can be really hard to find the right people.
As noted by others personal referral is by far the best way to get a "dream" job, as the employer already has a good idea that you'll "fit" in the organisation. Skills are only part of the picture, to do well at a job you'll need to have the right personality and relate well with your colleagues.
So, ask around, and get chatty with people who know lots of people. (Hard, I know!)
The way job boards work (at least, in the UK) is that employers will draft a job spec and pass this on to an agency, who in turn edit this and post to the job boards. They also trawl through CVs that have been posted to the board in search of candidates that match.
That's the theory. Here's the practice:
Job specs get filtered so much that sometimes they end up meaningless. A manager gives the spec to HR, who re-write it; it then goes to an agency, who may re-write it again. So the spec doesn't really represent what the job means and nobody qualified applies. Everyone loses.
Qualified people apply for the job, but their CVs get filtered by a non-technical agency recruiter and a non-technical HR person. The result is that a perfectly decent candidate gets filtered out because they don't have exactly the right acronym on their CV. Everyone loses.
Where I personally find the job boards useful is to get an idea of the decent agencies and the staff there who actually understand there is a person behind the CV. This takes time - several weeks - but if you apply for jobs that match your experience and interest you'll quite probably get a "bite" from an agency on every fifth application, on average.
If you do - talk to the agent and find out what else they have. Then keep talking to them, weekly or so, to see if the situation has changed: quite often you'll find they'll start to talk to you about jobs they've not even posted to the boards.
Note that the major IT job boards in the UK (cwjobs, jobserve, jobsite) send email to recruiters when your CV is updated. So, update it regularly - once a month is about right, I think - and you'll quite possibly find that you get calls for a week or so following the update.