You should definitely go! It's a very casual and very friendly atmosphere - everyone is always welcome. I try to stop by once or twice a week myself and find it very relaxing. It's also a great way to learn how to identify raptors. If you want to be helpful, don't worry about trying to identify birds and try not to count out loud (it can cause confusion). Just tell the group when you see a potential raptor coming and do your best to describe the location (eg: over the lake, over the poplar tree, over Kingston road, etc). You'll get the hang of it as you listen to the group. Looks like a mild North wind for the next few days so there should be a few good birds to see. You just never know what will fly by at Rosetta! Peak times are generally between 10 and 2, but birders (and birds) come and go all day. Also, be sure to dress warmly - you'd be surprised how cold you can get just standing around beside the cliffs.
Enjoy!
-kris
here's the link to the website:
http://www.raptorwatch.blogspot.ca