I’m thinking about adding a side bar to my theme. What are some widths that I should keep in mind?

Should I make it a separate theme all together? I have to think about it some more, but any input is welcomed.

@mandaris The sidebar I added to my theme is around 15 em, which seems to give enough room for links that aren’t to long. It only appears when the viewport width is larger than 776 px, which means it’s hidden on phones and tables in portrait mode, but will be displayed when they’re rotated to landscape.