Layout Opinions

I want to get everything done in my head and on paper before I start getting a design and programming done, and I need some help on a layout.

I know I'm going to have a header and navigation, but is having the navigation horizontal below the header a better solution than having just small text links on the sidebar?

Next question is whether I should have my sidebar on the left or right side of the content. I have made up my mind that I won't be needing two sidebars, so which side is more common for users? Right is used on most blogs and stuff, then left is on most forums and some sites. Which would be better?