My New Built PC won't Turn on

[ThisIsADumbName]

Today i assembled my first computer. I followed the manuals provided with the parts. However, when i finished and plugged it in, it didn't turn on. There was no beep, or even any sign that the computer was on. Can anybody help me figure out what's wrong?

Parts
Asus H81M-D PLUS Motherboard
Intel Pentium G3258
Corsair CX500m PSU
Asus R9 270x 2GB
G.Skill 8gb Ram
Seagate 1 TB 7200 rpm Hard drive

Thanks in advance!

 

[Vic 40]

First look at these steps,
http://www.tomshardware.co.uk/forum/261145-31-perform-steps-posting-post-boot-video-problems
maybe at the same time rebuild and check via these.