Is there a tutorial on how to build a laptop??

[SpaceLama]

And also how do I know what charger I would need

 

[hang-the-9]

If you are looking to save money doing this, you won't.
Basically you buy a shell including the motherboard, keyboard and screen, then add your own CPU, RAM, hard-drive and video card if it has a removable slot.

https://www.google.com/?gws_rd=ssl#q=laptop+barebones+kit