Like someone said before get rid of the advertisment and maybe replace it with a logo or something, will make it look much better. If you don't want to get rid of the ad then maybe place it in the footer or on the side of your site.
Once you get the hang of editing it, you can see how simple it is. For instance this site was our old ObsessBlue design http://www.virginatlanticva.co.uk/josh'>http://www.virginatlanticva.co.uk/josh we used this template as a base and started editing it from there and this is what we have now http://www.virginatlanticva.co.uk which only took 2 days to do!
A good tool I find useful if your using Firefox is "Firebug" you can edit the HTML, CSS etc from firebug without having to edit the files of your site so say your not sure how to do something you can change it in Firebug and it will come up so if you do it wrong just refresh the page and its gone and if you do it right then just copy it to your files.
Could you explain a little bit more, what exactly happens to the data?
Need any help feel free to PM me or something, Im not the best at editing but I'll try and help ya out.