Hello,
Check out the code from this skin
Andreas 01To center we use in the body and #wrap:
margin:0 auto;
For the others, it's hard to work it out without looking at it live, what I would suggest is viewing this tutorial:
Troubleshooting DotNetNuke SkinsIt outlines the techniques I would use to work out those problems.
One of the first things I would check is the widths that you have assigned to the various elements, that's usually why you get wrapping occurring