On my test blog here: http://exp212.blogspot.com I have a rather large gap between sidebar and main body. What do I need to be looking for in my template so that I can close it up? The block of code for both my sidebar and main are as follows:

#main-wrapper {
margin-top: 38px;
width: 510px;
float: $endSide;
word-wrap: break-word; /* fix for long text breaking sidebar float in IE */
overflow: hidden; /* fix for long non-text content breaking IE sidebar float */
}

#sidebar-wrapper {
margin-top: -22px;
width: 100px;
float: $startSide;
word-wrap: break-word; /* fix for long text breaking sidebar float in IE */
overflow: hidden; /* fix for long non-text content breaking IE sidebar float */
}

Is there where I need to be looking?

well, the only thing I can imagine that will bring those two elements together is if you. Set a width for content-wrapper.

Its actually doing exactly what your code is telling it. The side bar, is floating left and the other is floating right.

Try setting a width for the content-wrapper and see if that will improve it.

give width to #outer-wrapper
i tested it with 650px, and it is ok

Thank you both very much.

Yup! That did it. Thanks again