Ok first take out role=”search” from the search code
<form role=”search” method=”get”
In the twitter button on the sidebar you need to add an alt tag
<img src="https://www.twitterbuttons.com/images/lbn/twitterbutton-0201.gif" title="By: sozemediagroup.com" width="120" height="90" alt="" />
You have two search forms on your site with the same ID, and if you’re going to have more than one of the same thing that ID needs to be a class. So change this in two places from this:
form role="search" method="get" id="searchform"
to this:
form role="search" method="get" class="searchform"
Then in the input box from the search you have to give one of them a new name since both are named “s”. So just change one to something else.
<input type="text" value="" name="s" id="s" />
A lot of problems being caused by the Adsense code and I don’t know what to tell you about that. Try googling WordPress adsense code won’t validate to see if someone else has come up with a solution.
It doesn’t quite like that Akismet image. I can’t really see why though. It seems to think there’s a div in the wrong place…
Ok then your “Links” in the sidebar is repeated twice, and both have the same ID. <li id="linkcat-953"
So if you can change that ID on one of them or maybe take out one of the Links listings.
The rest of it seems to be caused by the Adsense.
Hope that helps!