Garmin question; how to mark events on a route

the_jackalcp

I'm new to Garmin products and have just got a 520. What I would like to do is plan a route and then mark things like the start of a climb, 3 miles to summit etc so that the info appears while I am riding either on the map page or flashes up on one of the data pages.

Can anyone tell me if this is possible and what the simplest way to achieve this is?

Thanks