I looked at this thread and it does not look simple enough.
Perhaps this will satisfy your request:
Select the emails you want to forward by clicking the box next to them.
In the "More" menu, choose Forward as attachment.
Type in a subject and whatever comments you'd like to add.
I.J. Kennedy has a great answer that you can check out, although I believe this is new functionality in Gmail which is interesting.
Another option is to load a Pop3 or IMAP client, connect it to your gmail, and then forward it that way. You could look for a client that lets you forward multiple emails at the same time, perhaps not as an attachment.