• Command (Mac) / Control (Win) + Shift+ H will show/hide all selected options in the Guides Panel.
• Command (Mac) / Control (Win) + R Show/hide rulers.
• Command (Mac) / Control (Win) + Shift + J Show/hide page bleed.
• Command (Mac) / Control (Win) + Shift + M Show/hide margins and gutters.
• Command (Mac) / Control (Win) + Shift + K Show/hide image cells.
• Command (Mac) / Control (Win) + Shift + U Show/hide dimensions.

HI, I JUST BOUGHT LIGHTROOM 3 & I LOVE YOUR TUTORIALS,BUT IAM HAVING TROUBLE FINDING YOUR LIGHTROOM SHORT CUTS. WHEN I STARTED IN PHOTOGRAPHY ( FIRST CAMERA 1978 CANON AT1) EVERYTHING WAS DONE BY HAND, I USE TO WORK DOWNTOWN (CHICAGO) AT PALLAS PHOTO,YOU KNOW B IG DEVELOPER TANKS & SO ON, SO I STILL HAVE A LITTLE TROUBLE WITH COMPUTERS, I WAS HOPING MAYBE YOU COULD SEND ME A LINK. P.S. 90% OF PHOTOGRAPHERS WORK I DON,T LIKE BUT YOU HAVE A GOOD EYE IF I HAD MONEY I WOULD BUY A LOT OF YOUR WORK, THANKS
Here is a link to some of the shortcuts, but you might be better off if you simply search the blog for the exact topic that you are trying to research.
LRShortcutsHandout