How do all temp agencies work??

The temp agency is responsible for paying the workers they send to a company. They charge the company a set amount per hour from which they take a percentage. The temp agency is also responsible for collecting taxes from the temporary worker's pay.

They collect resumes of people looking for work and match them with positions that are open from companies that are looking for temp help and do not want to spend time on HR costs, so they pay cash to the temp agency at a rate much higher than you get from them. I temped for a few years, and I NEVER wanted for work, and they wages they paid me were quite competitive, though I did work for an agency affiliated with the federal government.  The feds love to work through these agencies because they screen applicants. 

When I see an add that looks on advertisement, I 

try to respond to it. I get disappoint when I reach a job agent. They don't have all the information I needed.

At 1 job, I was doing work that I haven't done in 20 years. 

First of all, there are no "low-skill" computer jobs unless you are referring to data entry.  Even then you must be able to do 5000 or more keystrokes per hour and they test you first to make sure you meet the criteria. You can learn office applications via the programs themselves or You Tube.  Many temp agencies also offer training via their website.  All agencies drug screen.  I worked for a temp agency as a second job for 7 years, so the post that says they kick you to the curb, is not correct.  If you are a good worker, take the assignments you are offered, and show up when you're supposed to, they will give you as much work as they can.

They find a company that needs warm bodies to fill useless and trivia job positions, they get 30% of what the company is willing to pay, and handle all of the payroll and HR work for those employees. I call them pimp agencies. They tell you where to eork, what you will do, and how much you get paid. If you last a year, they kick you to the curb and never call you again.

What kind of computer work do you want to do? general office stuff? See about learning a skill so you don't have to do manual labor. What's offered at your local tech college? Temp jobs are all different. some are truly temp, others let you hire on after a while, it depends on the assignment. you need to ask the temp agency.