@Lissie - I took a look at the other thread but I dont see how to have 4 products on a line instead of 3. Once I figure it out I will be getting rid of the sidebar so there will be plenty of space to expand on my page.
The products are automatically aligned to the left. If you make the image and the surrounding box smaller, it will fit more per row. If you make the image and the surrounding box bigger, it will fit less per row. You'd just have to figure out the width and height of the image and the box.
The first line of CSS is for the box, the second line is for the image. You'd have to reduce the size for both. Keep in mind that the box should be 30px wider/taller than the image. You've got to play around with it.