I am new to LR and wish to install it on Mac where I have used iPhoto.
I have grouped many photos into the Events in iPhoto. Do I lose my Events history? This has been very useful but iPhoto has become unstable with so many images as I believe it is not designed to handle large quantities.
Do I load all my 60k photos into LR or are they available as part of the installation process?
Sorry no one has gotten back to you.
There are extensive tutorials available on the webs to help newbies migrate from iPhoto to Lightroom.
Try youtube and a general google search. If you have a large bookstore nearby, go browse the Photoshop section to see if they've got some Lightroom books.
Events are just metadata tags in iPhoto, based on date/time and sometimes GPS. I've never actually opened my latest iPhoto library to see how the images are organized. Some iPhoto libraries are not immediately accessible by other apps and you might find you must first export copies of your images before you can import them into Lightroom. If you do that, you can, of course, organize them in any way you want.