I speak from a position of experience, My BS and MS are both in Comp Sci.
I know very little about loans or finances.
That is very unfortunate as you are obviously an intelligent human being. Perhaps this is a good time to pause your formal education and get educated in personal finance. To me, it is that important.
I study computer science, and am thus confident that I will be able to find work after I finish school.
This kind of attitude can lead to trouble. You will likely have a high salary, but that does not always translate into prosperity. Personal finance is more about behavior then mathematics. I currently work with people that have high salaries in a low cost of living area. Some have lost homes due to foreclosure some are very limited in their options because of high student loan balances. Some are millionaires without hitting the IPO/startup lotto. The difference is behavior.
It's possible that someone in my family will be able to cosign and help me out with this loan.
This is indicative of lack of knowledge and poor financial behavior. This kind of thing can lead to strained relationships to the point where people don't talk to each other. Never co-sign for anyone, and if you value the relationship with a person never ask them to co-sign.
I'll be working as a TA again for a $1000 stipend.
Yikes! Why in the world would you work for 1K when you need 4K? You should find a way to earn 6K this semester so you can save some and put some toward the loans you already acquired. Accepting this kind of situation "raises red flags" on your attitude towards personal finance. And yes it is possible, you can earn that waiting tables and if you can find a part time programming gig you can make a lot more then that. Consider working as a TA and wait tables until you find that first programming gig.
I am just about done with my undergraduate degree, and will be starting graduate school at the same university next semester.
To me this is a recipe for failure in most cases. You have expended all your financing options to date and are planning to go backwards even more. Why not get out of school with your BS, and go to work? You can save up some of your MS tuition and most companies will provide tuition reimbursement.
Computer Science/Software Engineering can be a fickle market. Right now things are going crazy and times are really good. However that was not always the case during my career and unlikely for yours. For example, Just this year I bypassed my highest rate of pay that occurred in 2003. I was out of work most of 2004, and for part of 2005 I actually made less then when I was working while in college. In 2009 my company cut our salaries by 5%, but the net cost to me was more like a 27% cut. In 2001 I worked as a contractor for a company that had a 10% reduction in full time employees, yet they kept us contractors working.
Recently I talked with a recruiter about a position doing J2EE, which is what I am doing now. It required a high level security clearance which is not an easy thing to get. The rub was that it was located in a higher cost of living area and only paid about 70% of what I am making now. They required more and paid less, but such is the market. You need to learn about these things!