Well the thing is, one of my relatives used to work at this particular agency and the owner of the company is really good friends with him, so I don't think I'll end up with shit jobs.
Unless that relative is your direct recruiter and will be filtering all of the bad jobs from you (and they know which ones suck and which ones don't), I wouldn't trust this. You'll probably get some new recruiter who has been doing this for a total of 2 months and . Every staffing agency gets good and bad jobs, and the bad ones usually go to people with no experience.
Most help desk/desktop support jobs suck anyways. But ones that are turned over to a staffing agency tend to be worse. This is due to the reasoning behind going with a staffing agency. It is often because the company has high turn-over with that role or has trouble affording that role. Either the customers suck, the managers suck, that particular job role sucks, the pay is awful, or people are overworked due to the company being understaffed. The other reason is that the company is in a bad situation financially and can't afford to deal with potential unemployment for laying people off, or can't afford a full-time person and just get temporary people to fill in the gaps.
Combine that with the fact that you are new and without many worthwhile real-world skills... you just are not going to get placed into a good position.
As I said, this totally changes in say, 5+ years of IT experience, especially when you get skilled with a niche or rarer skill (linux administration or C# programming, for example). This is because the reasoning companies use staffing for those roles is fundamentally different.
most of the temp jobs he gave out were for one of the biggest IT companies in the city.
That doesn't mean those are good jobs. Some decent and larger companies still can have poorly run help desk call center roles that no one wants to do. The main thing to figure out is why these temp roles are available in the first place. If it's because all of these positions have people going on maternity or sick leave (not likely) then that's no problem. If it's because the company just can't find people with those skills, that's no problem. But likely, the company has something going on that prevent them from finding people who want to work there through normal means.
I have a couple of friends that graduated with me that have gotten consulting and administrative positions, so I wouldn't rule those out for me.
They had literally no IT experience and then got a job as a system administrator?
To add to this, most staffing agencies I've dealt with when I was more of a beginner were just a straight up waste of time. I was either thrown useless 2-week contracts (it takes at least that long to be useful at any job), 2 month contracts hours from my home in call centers, or they would have nothing for me, but expect me to not be with any other agency. I had a BS in Information Technology and a few certs, btw.
To me, unless you have had a solid 4-5 months of applications and at least 10 interviews with real companies for full-time roles, I wouldn't bother with a staffing agency.