The sun shines most on the south side of your house. If you have windows on the south side, they can let in the sun's heat and warm up your house. You can ask your parents if you don't know which way is south, or you can use a compass to find out. Where I live, it gets cold in the winter, so my solar house uses the sun to help me stay warm.
On a nice sunny day, you can see for yourself how much the sun can heat things up. Make sure your mom or dad helps you with this! Get two cups that are the same size and color. It's best if they are a dark color. Also get two pieces of cardboard that are a dark color, or use crayons to color them black.
In the morning, fill both cups with water. Put one by a window on the south side of your house and one by a window on the north side. Make sure the shades are up on the windows. Cover each cup with a piece of cardboard. Wait until the end of the day, when the sun is starting to set, and get both cups of water and taste them. The water that was on the south should be warmer, because it was heated by the sun.
Do you want the sun to warm up your house? If it's usually warm outside where you live, you probably want to keep the sun out. But if it's usually cold outside, the sun can help keep you warm.