The floor press will build massive triceps and lockout strength. The purpose of the floor press is to work the top-range of your pressing. Since you aren't able to use any leg-drive, as you would in a traditional bench press, most people can't handle the same loading. This will actually allow you to recover faster between workouts.
The floor press can provide insight into whether or not your bench press technique needs work. It says a lot if your floor press numbers are close to your bench press numbers. It indicates that you're not effectively using your legs in your bench press.
You can do floor presses with a barbell, dumbbells, or specialty bars like a football bar. Typically, the floor press will be done with max effort work, building to a 1-5 rep max, but that's not to say you couldn't use this with higher-rep ranges.
Floor Press Review
Watch this video to make sure you nail the floor press.
Dumbbell Floor Press
Try a pronated grip for this, engage the triceps, and keep your knees bent to make it more back-friendly.
Medicine Ball Floor Press
Try a less conventional implement, like a heavy med-ball for a high-rep finisher. In this case, you'll need anywhere from 75-150 pounds to get the job done.