Also go to /r/buildapc. They were a great source and help when I was first building mine. Learn how to build a pc from there first and what components you'll need, then start looking for parts.

Once you get to that point though and understand the process, my advice, for your rendering and post production needs, the most important thing you'll need is a beefy CPU to handle all of it. You'll spend a big part of your build on the CPU and RAM. Personally, I use an Intel i7-4790k and I think it would be a good affordable CPU choice for you. It handles everything great and I shouldn't need any upgrading for a few years. As far as RAM, get 16GB and you should never have an issue editing and rendering.

Any other components won't be as important for your workflow needs, so just research what you feel would be best for your wants in a pc and your wallet. So for example, your Motherboard, Power Supply Unit (PSU), Coolers, Graphics card (GPU), Fans, Mouse, Keyboard, Monitor, Tower, etc. Just go with things that are compatible with one another and just research so you feel confident you'll get your money's worth for the brand your interested in.

Then just put it all together omce you've found your build for a good price, and you'll be good to go.