You can hold down the Shift and left click a link or bookmark to open the link in a new window.

Hold down the Ctrl key or middle-click a link to open the link in a new tab.

Thanks, that helps. Any way to change the default?

Probably not. There are a lot of tab related extensions that can divert a link that opens in the current tab to a new tab, but I don't know if opening links in a new window is supported by extensions like Tab Mix Plus.

What am I not understanding? Right click on Bookmarks toolbar item>Open in new Window.

The OP wants to modify the default left click action and change it to open a link in a new window and that is not possible AFAIK.
It is easier to hold down Shift and left click then to open the right-click context menu and select the Open Link in New Window entry.

Yes, I would prefer to hold the Cntrl key to replace the open window, rather than open a new tab. I thought it was clear when I said "default" that a click would do what I wanted.