My First Gaming PC Build

Hello I'm planning on building my PC during the winter and I was just wondering if there is any advice you guys could give me? Some dos or donts. I'm not to educated on computer parts so if you could help me decide which graphics card to get, nvidia or Radeon or any other ones.
My budget is $400-$600 so if there are any builds that are out there now that you recommend please let me know. (Ones that include mouse,monitor, and keyboard would be nice too)

And how often do computer parts come out? Would I find myself buying parts in a few months just to upgrade? I'm not looking to have 4k settings just be able to play upcoming games like the division fallout4 at pretty decent graphics and frames.
Thanks ahead of time!
 
Back