kitchen sink plumbing hook up
If you really want to go through this effort (rather than just capping off the lines), then you should just install the lines into the walls (if they aren't already).



Normally you'd just cap the lines off until you're ready to hook everything up (as seen in my picture above), but there's nothing stopping you from putting valves on instead of caps, which is a great idea anyway (it makes it easier to hook up, service later, etc). 

With the pipes in the walls, you can freely work on the floor and install cabinets without worrying about them (and as you can see in this photo, it was before I had flooring or cabinets in).



Here's the same connections (with valves) after installing cabinets and the new sink: 



Nothing stops you from using valves instead of caps, though it does require cutting a bigger hole in the cabinet to install. Depending on your cabinet style you may or may not like this -- in my case these are pretty cheap cabinets installed in a laundry room in the basement, I wasn't too worried.

Just be sure you don't accidentally knock the vales open while you're working, or you'll ruin the floor that you're not even finished installing yet!