Well, the .htaccess file updating depends sometimes on the permalink setup ya have or what not to, as far as I know. But for the newer/easier guestbook setup...here's the url for it.
< -Below here is the instructions she gave recently I believe, from here down ->
http://geeksmakemehot.com/defaultguestbook.txt <- go there, select all the text, copy and paste it into Notepad or Metapad and save as guestbook.php and upload into the default theme (The Theme You're Using Now) folder.
2) In your dashboard, go to Write/Page (Which is the Guestbook page if ya made it already....under Manage..)
3) Under page options, select guestbook under page template
4) Add a disclaimer or what not to the page.
5) Volla! Your guestbook is set up and users can start leaving uncategorized messages for you!
6) Their messages will be posted as comments and will be styled just as the comments on your posts.
Hope this helps... or do you have a link or contact email for someone to talk ya through it via MSN Messenger or Yahoo or something?
P.S. As for the Paged Comments plugin, I don't think you really need it with her Guestbook plugin... it's just an added feature for it. Most like it though cause it's nicer for navigating through the guestbook's posts.. If you don't feel comfortable adding it, then I wouldn't lol..