Difference between float and align property in CSS

Align - You use align to align text and other items rather it be left, right, centered, or justified. Align DOES NOT remove the item from the document flow.

Float - Floats an object to the left or right and REMOVES it from the document flow. (i.e. A thumbnail image with paragraph text flowing around it -- you will usually need to set some margins on the image so it looks right).

You will most likely be using float to lay the page out. I would suggest the useage of a grid system. Here is the easiest, most compatible grid system I know of to date. http://webdesignerwall.com/trends/960-grid-system-is-getting-old

Also you will need to understand what using the classes "first" and what the CSS clearfix does. You will also need to understand generating a baseline grid (vertical grid, not just horizontal) so that all elements not only line up left to right but up and down as well.

"text-align" applies to the content of a box, while "float" applies to the box itself.