How to list most recent posts horizontally instead of vertically?

I’m not sure what theme I want to use yet (probably the Structure theme by Justin Tadlock), but I want list the most recent blog posts in a horizontal row of 4, then have it drop down to the next row and list the next 4, and so on.

I want the posts to show up in the main container section. The only difference is I want them to be listed horizontally with 4 per row.

Example:
9 8 7 6
5 4 3 2
1

Instead of:
9
8
7
6
5
4
3
2
1

Sorry for the poor description. I’m not a programmer, but I can figure most things out with a little direction.

Any idea how to do this? Thanks for the help!