It's a little tricky, but I found a workaround. If you select content that Scrapbook recognizes, the tablet highlights the content with a light blue box.
If the browser is in full screen or dual screen mode:
-Chrome, Firefox, and Dolphin: select a portion of the screen results in a picture while selecting the entire screen gets you a picture of the address bar and a link.
-Stock browser: very carefully select the entire screen and you get a screen shot and the link. You have to be very careful. It's really annoying.
However, if the browser is opened in a pen window:
-all browsers: just circle the pen window quickly and you get the screen shot and the link. Scrapbook selects everything when you're about half way through your circle.
I found this all really frustrating at first. But you can open a pen window almost the size of the full screen very easily (you only need to outline half a square), and then you're all set to minimize and multi task.