Finding a job these days is an art and a science. There's no harm in peppering the world with your resume, but truth be told - it's an unlikely way to get hired. Businesses aren't hiring resumes these days, they are looking for known quantities and the slightest connection can count for a lot. You'll need to prevail upon friends and family and the family of friends and the friends of family. If you've been able to work an internship or two, or had a part-time job off campus, be sure to contact people at the company you left for leads inside and outside the company.
Here's a general strategy that can pay off:
Pick a couple of companies you are interested in and search your contacts to see if there are any connections. And I mean all of your contacts for any slight connection. Doesn't matter what department or job - you just want a contact at the company. This is where LinkedIn is useful. If you find a contact, ask them about the place, what's important to the company, and of course whether they are hiring. Ask them for a contact in their company's HR department you can talk to.
If you can't find a contact, call the HR people directly.
Be honest about your intentions. Tell them you are an entry-level or junior person and you'd like to know more about opportunities in their company and in the industry. "I'm looking for a job [or going to be looking for a job] and I have some general questions about your company and the industry even if you don't have a opening for me. Do you or someone else have 15-20 mins to talk?"
Even if you get some underling, you are going to get valuable information. Make sure you've gotten some background about the company and have some questions prepared. Don't ask them "So what does Schmendrik, Inc. do?".
Even if they don't have an opening for you, tell them you are trying to understand what's important in the industry and what skills they might look for in the future. Ask the HR person who they are hiring, what skills they need. Ask them what entry-level roles they hire into. You are trying to understand what is important to this company so you can be prepared when there are openings. (This can be a really effective strategy if you do it before you leave school. Then go get some of those skills.)
Ask whether they would give your contact info to someone in a department you're interested in, so you could get more information about the specific jobs.
Ask them whether they anticipate openings in the future, do they know of other companies who are hiring, do they have contacts at those companies? Then follow up with those people.
If the call seems to be going well, and you feel comfortable with the idea, see whether someone in HR will go to lunch with you (you're buying) and ask more questions.
Important: be gracious and respectful of their time. Thank them profusely. If you can get an email address from them, send them note.
If HR won't talk with you, but you have contacts at the company, ask these same questions of your contact.
If you don't have any contacts at your target company, get on the internet and try to find phone numbers into the company.
Call or email them back occasionally to see whether there are jobs, but don't be a pest. Once every two months is plenty.
If there are openings in the future, make sure the people you've talked to know you are applying.
Here's another way to find contacts in your target company.