Web application architecture

Which architecture is the best for web application as we know that we have web 2.0 standards, techniques? So as we know that business application should be SEO friendly so I am so much confused to choose best and re-usable designs.

What exactly are your "web 2.0 standards, techniques"? As far as I know there's no web 2.0 standard, its just a nice buzzword to try and get people to pay to upgrade their sites.

As for the "best architecture", there could be 1,000's of them. It all depends on your system, and what you want it to do. The architecture for eBay is going to be completely different to the architecture of Facebook, and it's the same with every other system out there.

well, i see you are new to web development, so i suggest you to start by looking at asp .net, with microsoft visual c# or microsoft visual basic, depending on your knowledge