it depends on the website. if its a promotional website like a website for a studio designers need to avoid scrolling. If its a content oriented website like a blog its common that you'll have a scroll. in the old ages browser scroll was a nono because it was a painful task but with the invention of the mouse scroll key huge scrolls became acceptable.

again it really depends on the website your talking about. also there is a limit to the amount of scroll a user can take. most blogs or content websites utilize pagination or Page 1 [2] 3 4 5 >>last method to avoid really big scrolls in articles and such. what ever you do DONT use iframes. they are mostly a pain in the ass and can cause double scrolling of the browser page and an iframe. 

if you do design a website that requires a scroll you need to point out important features and actions like navigations and such at the 'first scroll' that a user see's. like a promotional banner if you wish or a Tagcloud for example that will display the minute a user see's it. anything below the first scroll is secondery. thats actually the principle that websites sell adspace also. also always use a footer with 'top' link to the header when a user reaches the end. use anchors to specific areas of the page and put a website link map on the footer so a user can continue his navigation without having to scroll up to move to somewhere.

i hope it was usefull to you.

:)