Hi Serenity,
Obviously there isn't a way to control the length of someone else's web page, so if it is too big to embed in the course screen itself I'd suggest you use the option to open the link in its own (separate) window. Whenever you add a link you'll see the option in the hyperlink manager that says "target", and then a dropbox lets you chose from options such as "new window", "same window", etc.