You own a server rack and a server, correct? The easy thing to do is buy Gruber rails, then you can slide the server on top of it.
More commonly you get a set a rails, part of which goes onto the server, and part of which goes into the rack. You then slide the server into the rack.
I dislike videos, but am too lazy to look further. https://www.youtube.com/watch?v=g8gTTFiOh84
Google something like dell rails for R710 and that should get you things. Or if you have a friend who works in a data center ask them. You also want to think about power and ventilation, but if you're just going to have one or two servers in a rack, that's probably not too important.
A link to Gruber rails so you can get an idea. They screw into the mounting rack and have lips that hold the server.
If it's Dell then I'd stick to Dell rails, I think they attach to the servers without screws.