Staffing Companies are the Iranian Arms Smugglers of the IT world. They buy low, charge high, and rarely deliver what is promised. The staffing company gets a multiple of what the pay you, and you can almost always do better on you own. I have hired many job shoppers thru most of the national staffing companies over the last 25 years and never have I gotten an intern from one. Staffing companies are for gypsie workers who can't or won't find or hold a steady job, for one reason or another, and need help getting their foot thru the door. Shoppers are by definition disposeable employees, brought on for short term activities not worthy of going thru the regular hiring process. That being said, I have been a shopper, got hired full time by the first company I shopped for after three months, and that job ended up being my first position that led me up into management, but that was because the company had a policy of bringing in all new hires thru the door via a job shopping house. This is the exception that proves the rule. While in that position for more than a decade, I hired many more shoppers, but only found one or two worthy of being offered direct employment.
I have also had half a dozen interns assigned to me over the last decade and every one was one who came to me (or my HR) thru their own efforts, armed with a succinct and well laid out resume, and most important of all, a thoughtful and captivating cover letter that told me who they were, what they wanted to do (or learn), what they could do for me, and asked me up front for what they wanted. This will be the hardest part of your learning experience, the process of selling yourself to a prospective employer. You will have to get over any natural modesty and shyness you might have and in this one area of your life, learn to be professionally extroverted.
To get my own internship, I researched the field and selected the employers I thought I might want to work for in my area. I read every magazine article I could get my hands on about any company I applied to, and their principle customers and suppliers. I made cold calls to the company and was personable and friendly with whomever I managed to speak to. I inquired who would be the best person at a particular company to speak to about an internship, asked about any internship or mentoring programs they might have, got copies of the rules, and wrote unique and individual letters to the responsible hiring parties, and sent thank you letters to whomever helped me find the names and information, and thank you letters to anybody who responded to an internship request, even if it was to san 'No". My best internship offer came three months after being blown off for the first request, and came to me thru a phone call from an administrative admin who remembered me and my thank you letter, when the previous intern moved on and the opening came up again. COSMIC SECRET OF THE UNIVERSE: Secretaries and Administrative Admins run the world. They can make or break your career. Always be polite and friendly with any admin you come across, always respond promptly to any request they make of you, and always make the effort to cultivate a good relationship with them.