The Problem (Why Visit?)
So you have graduated with your degree and have been doing your best contacting and getting to know people in your field. You have applied to dozens of places online but only a fraction have even acknowledged your existence by sending you a generic job denial email. So what do you do? You tried to "network" in collage but nothing panned out. Most places you have visited are not even offering jobs. However, there is much more to be gained through visiting companies then a binary yes or no. When executed properly, visiting companies can help you meet new people, learn more about your industry, gain business skills, and encourage yourself to keep pursuing other opportunities.
Though more traditional jobs may not require this approach, chances are if you are reading this you may be trying to get into a more difficult industry to approach like acting, film, or video game design.
How to do it
The first and most important part is to actually do it. This is strange advice because of the obviousness of it, but it can be very intimidating to decide to visit a company that you respect and want to work for. Though people say that "you can only make a first impression once", any impression is better then not making one at all.
So now that you have decided who to visit, you need to find the companies location. In my case, in the game industry, I went to a helpful site that listed every game studio in any city (link). The best place to find the address of the company is under their “about” section, at the bottom of their website, or look on Google for larger companies. It is also not a bad idea to check the street view of the companies address to insure they have not moved; or plan to visit several companies that are in the same area of town so you do not wast your time going to an old location that the company is no longer at.
After planing a trip, which you should expect to be the first of many, what should you bring? Though it varies based on occupation here are some items that should cover your basis.
Resume: Make sure it is updated and list your contact info and portfolio info in an easily noticeable spot.
Paper an writing implement or be comfortable with taking notes on your phone. This will be needed to remember the answers to the questions that you will ask (See questions sections).
Business card (bonus): Though great to have, do not let the lack of business cards stop you from visiting companies.
Portfolio info: Should be on your resume. However, a physical presentation such as a small book or folder of some of your best work can be a massive bonus when showing your skills.
In terms of what to wear do not let this be a limiting factor. It is recommended that you dress appropriately for your job and not wear anything vulgar or offensive but do not let the fact that your best jacket is at the dry cleaners stop you from making your trip.
The Really Important Part
Questions: So after visiting one location that was closed you have finally encounter a human being that is asking you why you are standing menacingly in front of their office as your sweaty hands slowly saturate the fresh resume you printed out for this trip. In this situation, though getting a job would be the best outcome, there is a series of question that will help you out even when moving onto other companies.
Are there any positions available? And let them know why you are asking. For example: "My name is Gabriel and I am looking to learn more about the gaming industry and was wondering if there was any positions available at your company?”
Who are you? Make sure to get the name of the person you talk to. Not only does this give a small connection for you and the people of the company, but if you get called back or see other members of the company most people will ask who first spoke to you. This is also a good time to introduce yourself and make sure they know your name.
Is there someone else that I should talk to? It is not likely that you will talk to the main manager the first time you visit. So ask who you should get a hold of or if there is a better time to stop by to see the people you can get the right information from.
Is there other places where I might find available positions? Though it is possible that they know of positions open at other companies this is not what you are trying to find out. The real prize is events that people in their field know about where there will be more people in their field. This is even more important in entertainment or creative fields then in more traditional companies. Through traditional companies will most likely will know about job fairs or places that you can learn about the skills they need.
Can I leave you my resume? This can be a non verbal question by holding your resume, and is a good way to pursue the person you should be talking to. You can ask "Who should I give my resume to?" which will most likely give you the name of the hiring manager.
No Soliciting (signs)?
The original intent of these signs is to discourage unwanted sales men and people looking for donations. But in some cases job hunting or applying for positions are specifically mentioned on the signs. Being mostly a personal issue in whether or not to ignore these signs, it is an option to go in and ask what the "proper" way to find a job is or who you need to contact to set up an appointment to use the "proper" channels. Another option is to mention the sign in your follow up email to your visit.
A Quick Disclaimer
Though visiting companies is a great way to network, be respectful. These are real companies that you are visiting no matter how casual the atmosphere and they have other issues to attend to. That being said most people that work at these companies (at least in the game industry) are extremely kind and helpful. When they turn you away it is not out of malice or a need to see you fail, but a simple lack of positions or having no need of the particular skill set that you provide. So be bold and ask for the things you need to meet the right people and find a job.
Best of luck and good hunting!