Welcome to the forum! There are a lot of great people here willing to lend a hand anytime. Often using the Search box (at the top-left of every page) will lead you to the answers you're looking for. If not, feel free to post a question in the appropriate area.
Please take a moment to view the information here to get the most out of your iPad as well as our forum:
When you upgraded to iOS 5 the Safari App updated as well. The short answer to your question is no, you cannot change it from the tabbed layout back to the old thumbnail layout.
That's probably not the answer you wanted to hear, but hopefully you'll get used to tabbed browsing.
