The best place to look for a job is rarely in online ads. Why? Not only because that is where everybody else is looking (and hence that most get thousands of applications a day) but also because the best jobs at the best companies rarely have to even advertise positions (unless they are highly specialized). If you’re looking for a general position that does not require long training, experience and expertise, then guess what? So is everyone else.
So what happens to companies that offer these positions? Well, they get plenty of applications without even asking for it. When friends and family members of those who work these jobs hear about how much they like it, inevitably some inquire about whether they can work there too. So these companies get filled up easily within the social networks of people that already work there.
However, that is not to say there is no room for outsiders. Of course a company is more likely to hire someone if they have a connection to someone inside the company (who can vouch for them, and also studies show that knowing someone within a company before hiring increases the chances of them staying and succeeding), but applicants that are persistent and stand out from the crowd have an excellent chance.
So my advice to where to look for a good entry level job is to tell everyone you know and meet that you are looking for a job (and ask them about where they work) and to do research on the very best companies in your area for whatever industry you may want to work for. For example, say you wanted a simple part time job that pays well. I’d look up to find out what the best wedding caters were in the area, and apply there. It may not be the funnest job, but it pays well and requires little commitment. Perfect for college students or those looking to supplement passion projects.