Customer Support for Digital Editions

There doesn't seem to be any support for Digital Editions? I just spent 15 mins. "chatting" to the technical team who then moved me on to the "forums" cause they don't provide support for Digital Editions?

I just purchased an ebook for $149.00 (a professional/medical book) and chose the ebook format thinking this would be great to read, just like I read other ebooks on my Kindle, but it seems that I can't highlight text using Adobe Digital Editions?

Can anyone shed some light on this please? And does anyone know if there a User Guide to Digital Editions, because this format is new to me and I'd like to know more what I can and cannot do with it.

Many thanks,

Marla