To ensure proper alignment when floating an image to the left, you should apply a margin-left
to the container element that is at least equal to the width of the image you are using.
For instance, if your HTML looks like this:
<img src="image.jpg">
<p>Some text
Assuming the image has a width of 160px, you need to add a margin-left
of at least 160px to the paragraph element (although a slightly larger margin-left will often look better).
Once you have floated the image, setting the margin-left
on the following paragraph is all that's required. You don't have to specify a width for the paragraph itself.
See a demo here.