I love the soft, moody feeling of photos taken by window light. The light skipping across your subject will illuminate texture and give you a lot of room to stretch creatively.
You can use direct or indirect light, each will give you a different feeling to your photo.
There are several ways I like to use window light. The first is shown in this photo above, where the light is coming in at 90 degrees (or so) to my subject.
The second, is to have the light coming in the window towards me, but at a bit of an angle so as not include the window in the composition. This angle beautifully brings out shape and texture.