As you probably know, you can view any of your commentaries or other reference tools in parallel with the text of the Bible. To do this, you just select the commentary you want from the Add Reference Tool Pane pop-up menu. Here are a few tips for working with commentaries in parallel panes.
Open a reference tool pane with a vertical orientation: By default, reference tool panes open in a horizontally-oriented pane below your Bible text panes. You can change this to a vertical orientation at any time by clicking the pane orientation button at the top of the pane. Personally, I always want my commentaries to appear in vertically oriented panes. After all, it’s generally easier to read all the text a commentary provides in a pane which extends the full height of the window. So rather than open a reference tool pane and then switch to a vertical orientation, I simply hold down the option key when I open a new reference tool pane. This automatically opens the pane with a vertical orientation.
Scrolling a reference tool pane: When you have multiple panes in a window, the scroll bar scrolls whichever pane is active, and the other panes stay in sync with that currently selected pane. Since commentaries often contain long explanations that require scrolling, be sure to select the commentary pane by clicking it before you try to scroll. Scrolling one of the Bible panes will simply take you to the comments on another verse. If you use a mouse with a scroll wheel or have a trackpad which lets you drag with two fingers to scroll, you merely need to place the the cursor over the pane you want to scroll. Accordance will automatically make that pane active.
Switching to a different reference tool: If you’ve read one commentary’s take on a verse and want to consult another one, you can simply choose a different commentary to display in the pane. You can do that by using the pop-up menu at the top of the pane, or by using a variety of keyboard shortcuts. Shift-control-plus and minus will switch the active pane to the next or previous reference tool. Shift-control-1 through 0 will switch the pane to the first through tenth reference tools in the list. So, for example, if you have NAC as the third item in the list, shift-control-3 will automatically switch the pane to display NAC.
Update: Doh! Never write a blog post in a hurry. Instead of giving the correct shift-control key combinations, I originally told you to use shift-command. Thanks to the commenters who caught my mistake, I’ve updated this post with the correct keyboard shortcuts.