edit blog posts

hello, I have edited a wordpress site so that images run horizontally accross the page, but when I add posts to the blog section the writing spreads the whole length of the page. Is there anyway of getting my posts to act like the images. here is the code i used to make the images function how i wanted them to:

.one-column #content {
	margin-left: 150px;
	width: 10000px;
        height: 500px;

        float: left;
}