Fuzzyred's Marvelous Reading Nook

So, my dad recently helped me dig a new patch in my garden, and I planted a rose bush in there. It was a Valentine's gift from my mom and spent a couple months in the house. Part of it is green and healthy, but a lot of the stems are brown and dead looking. I don't know what to do to save it. Do I leave the dead parts there? Or do I trim them down the ground in hopes of making the healthy parts stronger? I don't do much gardening, and I'm sure sure how to keep roses healthy, so any advice is greatly appreciated.