I've built my own PCs for the last 22 or so years and that kind of knowledge and experience can't really be summed up in a few forum posts, but I'll summarise the important points.
In my experience, very few PC builders "get it right" when it comes to compatibility between different components. Sure you could put together a reasonably decent machine, but if it means you need to reboot it every few days, weeks etc... just for it to remain stable (even on Windows), then it's not an optimal hardware configuration. If you don't know what you're doing intimately and know PC hardware inside out, I'd probably lean on buying a decent pre-built brand (but do your homework).
Work out what operating system you're planning to run, if it's Windows 7, you're severely limited by choice these days as most hardware and drivers are designed for Windows 8 and up.
Start with first building block, that's your motherboard. Decide on a board then work your way up.
There is no "one size fits all" approach to building a PC. One machine won't be "the best" at everything. A machine which is great at high-end video editing isn't necessary good at playing high-end games etc...