It's getting more and more common for students to ask about building their own PC. I thought I would collect some links to get them started:
Take a look at Logical Increments first. They have a very straight forward listing of what you should buy if you have a certain amount of money. You can go up a few levels or down a few levels on the individual parts to customize your computer to your needs. Down below their tier list, they have excellent writeups that explain all of the parts that go into your computer and what to look for in them. I highly recommend reading each of them (click on the little arrow to expand each article).
If you want some help figuring out which CPU to buy, then CPU Boss has a pretty good setup. You can sort the CPUs based on different criteria, but I usually look at their "Performance Per Dollar" chart.
The same people also run GPU Boss, for comparing various graphics cards. Note that these are not the best sites for getting information about specific graphics cards and CPUs, but they are good places to start and very beginner friendly. If you want more in depth information, looks at Tom's Hardware.
Once you have a pretty good idea what you want, head over to PC Part Picker and click on "Start a System Build". This site helps you figure out if your parts are compatible with each other and does a nice job of showing you where you can buy your parts for the best price. You can also look at the PCs that other people have built. Here are some of mine
For a little more help with keeping your prices as low as possible, take a look at the Build A PC Sale subreddit. You can search by product type on the right. Speaking of Reddit, the people from the Build A PC subreddit have a nice guide for people who are building their first PC.
You might also want to look at the refurbished graphics cards from GPU Shack. That's where I usually get my cards (their selection changes a lot, they don't always have what I'm looking for).
When it comes time to put your PC together, you should watch some videos of other people doing it. I don't have any specific suggestions for good ones. Maybe ones from the above sites? You're welcome to bring your parts into school and we can put it together here.
Some specific advice: