How to: Columns

Hi, sure this thread have a lot of questions, but the search no returns results.
I have a problem to set columns in the right way, have a ‘about team’ space, where I want to put 3 columns, 2 items each column.
The 3 first item of each column, have good position. but, the fourth, stay right down of the third item.
I don’t know if can understand, so here’s a picture: http://i.imgur.com/BD9e5va.png
I’m using something like this to make the columns.
[cols]
[col class=”1/4″]
Something in the column.
[/col]
[/cols]
Maybe you can give me a link to understand the behavior of columns on WP, or something like that.
Thankyou in advance