you want to connect your sata devices last. it to easy to snap a sata port off. I put the ram..cpu into the mb outside of the case after i check the mb cpu slot for bent pins. (good led flash light and a magnifier). with the mb empty line up the mb standoffs to the mb. (dry fit) you need an extra hand when you put the mb in...have to press the mb against the case i\o shield.
try not to have the pci 4/8 pin power cable go over the video card. you may have to by an extender cable to lay the cable around the outside of the mb. pick up a some plastic ty wraps from local auto parts or hardware store. most of them come it muilt sizes and colors. most people dont cable there system right and a fan wire or power wire will get sucked into a fan and get cut. or it stick out and get sliced by the side case door. ram..cpu..sata cables are all keyed. they only go in one way the right way. dont force anything..i seen people snap ram slots and short ram out by forcing it in the wrong way. when you buy your mb and cpu and ram make sure the ram on the mb qal list or been tested by the ram vendor in that mb. with the cpu check to see if you need a bios update to get the mb to post. some older amd and intel mb do need cpu code updates to post. older x6x chipset from intel and ib cpu. most mb guilds will have a list of cpu and bios needed to have the mb post.