I'd like to know where I can learn something..

there are some good video on you tube on how to build and test pc. there also the dummies book on repairing pc.
basic field service kit would be a laplink kit. with usb..ser and parrel cables.) you can find these kits for 30.00 online. good for moving data from old to new pc. if the pc is dead..dead then a usb to sata/ide kit can save your can. you need a good set of screw drivers. a volt meter. http://www.hirensbootcd.org/download/ boot cd with tools like that. a dos dig or burn in like ami diags. a post it card for no video systems. good kit will have know good pci video card and power supply.
online there the a plus cir test...mse for networks. (great for basic info on networks and ip of how a network card works).
microsoft has free or almost free for people tecknet. (they also have free training days on how to install windows (custom installs and installs where you can load your own software and back out of the oem reg screen).
if you have a local micro center or ebay..look at getting book staring with basic ac circuits and formulas. tell you how to read a cap..how to read a mb repair blueprint or tv. then go onto digital circuits. vendors like intel and others do list and have cpu conferences yearly in the us. if you hasve the money to attend one of them. if you want to have fun then try and be a beta tester for vendors. if you have the work bench and the skills it fun to get new hardware and software and put it to the test.