Lot of good advice, pro's to building yourself cheaper than custom made, experience in self repair, and as said above, con's if you mess up you have to re buy the parts, chances of latter very rare nowadays only thing you will mess up on is the CPU, and that is if you don't put paste onto the surface correctly, which isn't that hard tbh, I have made a lot of desk tops in my time, no biggy.
It all depends on your $ what you can afford, you will not get guarantee, on self build the same as you will on some company's, you can make a sufficient build always depending on what you want it for which is the main concern, what do you want a gaming pc, a pc that is good for visuals as in using software for vegas pro, or just a all rounder, I can give you links and will give you one, from a gamer who used to do this for a living, no one as the best answer,, as the hardware and software does change that often its really mad to keep up with, but, myself I am thinking of building another pc with this build, maybe a few adjustments.
Now that was a few months ago, and im UK im not sure where your from, but that is a very good rig, but it will give you a good guideline to go from.
Google is your friend, YT ( You Tube ) is good, but read the comments reference other peoples experiences, you will get a lot of peeps, saying this is not right etc, but they have not either listened to the info correctly, ordered the right parts, or are genuine loons, it is simple as peas, but if you want warranty's etc then go for pre builds, I would also go for windows 7, 8 and even 8.1 is bs, and is made more for apps ipads etc, im not going to argue on that one, but its pants, windows 10 is a vast improvement on the latter, but waiting about is your call, if you have a old pc, with windows 7 hanging about not doing anything then use the code on that, for your own new build, you can and are allowed to download Windows 7 OS and install either with USB or disc etc, onto a new rig, as long as you don't use the old one again.
You will also get warranty's on 99% of your items you buy, to build your pc, keep the receipts, if a part goes wrong etc just claim back, but if you OC ( over clock ) on certain items as in graphics card, RAM and CPU, then you can lose that privilege, you can also buy lower ended pc's that are overclocked pre made, another option, never buy a pc that is pre conditioned, as in someone else had it, and it as been wiped of all their accounts and reformatted etc, and set back to factory settings, this is a no no, and ive found a lot of peeps very unhappy with this, as always its your call, just putting my two penneth in as other peeps have <----- UK saying,,
Just to clear up something above, when you buy from a seller pre made, etc you usually get a longer guarantee than you would do for the parts separately, but, tbh no one ever worries about that, as you will most likely upgrade as you go along, graphics card, ram, hard drive as in SSD and even CPU, that's how it goes tbh, I've always stayed a couple of steps behind latest builds and upgraded when I feel the need to, there is no need whatsoever to have the latest all singing dancing computer, it as always depends on what you want it for, MC hardly uses your pc compared to say BF 4 or the latest games out there.
Any hoot good luck with whatever choice you make, and if stuck, all peeps above and myself inc will help you if needed