Two columns

Hello everybody!

I’m working with template Shaan that has two columns, a big left one for writing and a second one on the right, narrow, for menus. The firt 4 pages is a web and the 5th page is a blog. I want in this first 4 pages to put announcements at the lateral column and in the blog page put menus like categories, labels, etc. The problem is that I don’t know how to do that in order to differenciate web pages with blog page.

Thanks in advance for your help.

Eva