You might want to try Clickwebinar for webinars. I have used their service seamlessly for a couple of months on MacOS and they do the recordings.
They are not good though if you need to constantly interact with the audience because the delay in speech through their server is too high (or at least was too much for my standards). In those situations, I presume Skype's or Google Hangouts screen sharing feature is just about enough.
If you need to record the screen even when using Skype or such, try SnagIt (http://www.techsmith.com/snagit.html)
Hope you'll find this useful.