Each such person whom you contact becomes a participant in your search. One of the most invaluable sources you have here in the Unites States is your embassy. Often foreign embassies maintain lists of contacts for employment. We suggest that you form a cooperative with other students from your country attending this program or another program in the area. You can split the work up amongst you and share the results.
Communication skills are very important.
If you have any doubt, ask your friends and fellow students for an honest opinion. Consider taking additional English language courses. Equally important are your writing skills. If you are interviewing with an American company or an American branch of a company, you should be aware that you are expected to conform to certain cultural norms. Your dress and overall appearance, your manner of speaking and the answers to many questions will be expected to match certain norms.