Wow, you really want to jump in eh! Before you go spending money on mining gear. Yes, absolutely watch videos on youtube on how to build a build a p.c. To be honest building a P.C is very simple in essence you need the following components to build a p.c

1. Motherboard, ATX with at least minimum 5 PCIe's slots (if building a mining machine you really need at least 5 PCIe slots to host one Graphics card per slot)
2. Power supply. Either one 1500w modular PSU or two 750w Modular PSUs
3. CPU (Processor) depending on the motherboard either and LGA1150 or LGA 1151 CPU
4. CPU Fan
5. RAM Depending on the motherboard either DDR3 or DDR4 memory
6. Harddrive (I prefer solid state)
7. Anti static Wrist strap
8. Thermal Paste to mount the CPU Fan onto the CPU
9. Windows OS (Microsoft have 90 free trials of their OS's)
10. Someplace to shove all the gear into, for a mining rig most people build a frame otherwise they stick everything into a case.

If you can find an old PC to take apart would be a great start get you used to all the all components, this would be purely for instructional purposes.

Once you are happy with building a P.C then all you need to add to the above list are:

1. PCIe risers to extend the PCIe slots from the motherboard to the Graphics cards
2. Graphics cards = These are the things that make the money

It's a real headache to get the right components if you are new to mining, but feel free to ask me once you have the basics under your belt or have any questions regarding the above

Cheers

Joe